[Related links: publications according to MathSciNet; articles from Web of Knowledge with citation data; Author Profile on Zentralblatt Math]

Journal articles

• Income inequality measure based on a Kumaraswamy-type distribution [with E. Deák, Z.-X. Mao, J.-F. Tian] (manuscript).

• Asymptotic behaviour of zeros of Bessel function derivatives [with P. Kumar, S. Ponnusamy]. Studies in Applied Mathematics (submitted).

• The radius of starlikeness of regular Coulomb wave functions [with P. Kumar, S. Singh]. Mathematical Methods in the Applied Sciences (submitted).

• The ratio of the generalized Marcum functions of the first and second kind: Monotonicity and bounds [with S. Sahoo, S. Singh]. Results in Mathematics (submitted).

• Infinitely divisible modified Bessel distributions [with D.K. Prabhu, S. Singh, V.A. Vijesh]. Pacific Journal of Mathematics (submitted).

• Bounds and Turán type inequalities for Ferrers functions of the first kind [with M.M. Rudrappa, S. Singh]. Journal of Approximation Theory (submitted).

• Bounds and asymptotic expansions for the radii of convexity and uniform convexity of normalised Bessel functions [with P. Kumar, S. Singh]. Analysis Mathematica (accepted).

• Infinite divisibility of some Whittaker lifetime distributions [with G.M. Assefa]. Journal of Analysis 34(1) (2026) 229-247.

• The Hermite rank of a special subordinated long-memory Gaussian process. Journal of Mathematical Analysis and Applications 554(1) (2026) Art. 129910.

• Irrational bounds for quotients of Whittaker functions of the first and second kind [with G.M. Assefa]. Proceedings of the American Mathematical Society 153(8) (2025) 3451-3466.

• Asymptotic expansions for the radii of starlikeness of normalized q-Bessel functions [with P. Kumar, S. Singh]. Results in Mathematics 79(7) (2024) Art. 248. [abstract in Hungarian]

• Probabilistic and analytical aspects of the symmetric and generalized Kaiser-Bessel window function [with T.K. Pogány]. Constructive Approximation 58(3) (2023) 713-783. [abstract in Hungarian]

• Infinite divisibility of the Whittaker distribution [with G.M. Assefa]. Proceedings of the American Mathematical Society 151(12) (2023) 5429-5442. [abstract in Hungarian]

• Exponential bounds for the logarithmic derivative of Whittaker functions [with G.M. Assefa]. Proceedings of the American Mathematical Society 151(11) (2023) 4867-4880.

• On starlikeness of regular Coulomb wave functions [with P. Kumar, S. Singh]. Proceedings of the American Mathematical Society 151(6) (2023) 2325-2338. [abstract in Hungarian]

• Asymptotic and numerical aspects of the generalized Marcum function of the second kind [with N. Bisht, S. Singh, V.A. Vijesh]. Applicable Analysis and Discrete Mathematics 16(1) (2022) 202-217. 

• Bounds for the generalized Marcum function of the second kind [with N. Bisht, S. Singh, V.A. Vijesh]. Ramanujan Journal 58 (2022) 1-21.

• Functional inequalities and bounds for the generalized Marcum function of the second kind [with N. Bisht, S. Singh, V.A. Vijesh]. Results in Mathematics 76(1) (2021) Art. 35. 

• Approximation of cdf of non-central chi-square distribution by mean-value theorems for integrals [with D. Jankov Maširević, T.K. Pogány]. Mathematics 9(2) (2021) Art. 129.

• Asymptotic expansions for the radii of starlikeness of normalised Bessel functions [with G. Nemes]. Journal of Mathematical Analysis and Applications 494(2) (2021) Art. 124624.

• The generalized Marcum function of the second kind: Monotonicity patterns and tight bounds [with N. Bisht, S. Singh, V.A. Vijesh]. Journal of Computational and Applied Mathematics 382 (2021) Art. 113093.

• Geometric and monotonic properties of hyper-Bessel functions [with I. Aktaş, S. Singh]. Ramanujan Journal 51(2) (2020) 275-295.

• Radii of starlikeness and convexity of generalized Mittag-Leffler functions [with A. Prajapati]. Mathematical Communications 25(1) (2020) 117-135. 

• Zeros of orthogonal polynomials near an algebraic singularity of the measure [with T. Danka]. Constructive Approximation 47(3) (2018) 407-435.

• Cross-product of Bessel functions: monotonicity patterns and functional inequalities [with S. Ponnusamy, S. Singh]. Proceedings of the Indian Academy of Sciences- Mathematical Sciences 128(3) (2018) Art.36, pp. 30. 

• Redheffer type bounds for Bessel and modified Bessel functions of the first kind [with K. Mehrez]. Aequationes Mathematicae 92(3) (2018) 425-439.

• Zeros of some special entire functions [with S. Singh]. Proceedings of the American Mathematical Society 146(5) (2018) 2207-2216.

• Radii of starlikeness and convexity of a product and cross-product of Bessel functions [with A. Szakál, R. Szász, N. Yağmur]. Results in Mathematics 73(2) (2018) Art. 62, pp. 34. 

• The Hurwitz-type theorem for the regular Coulomb wave function via Hankel determinants [with F. Štampach]. Linear Algebra and its Applications 548(1) (2018) 259-272.

• Zeros of Bessel function derivatives [with C.G. Kokologiannaki, T.K. Pogány]. Proceedings of the American Mathematical Society 146(1) (2018) 209-222.

• Bounds for radii of starlikeness and convexity of some special functions [with I. Aktaş, H. Orhan]. Turkish Journal of Mathematics 42(1) (2018) 211-226.

• Radii of starlikeness and convexity of Wright functions [with E. Toklu, E. Kadioglu]. Mathematical Communications 23(1) (2018) 97-117.

• On the generalization of the Lambert W function [with I. Mező]. Transactions of the American Mathematical Society 369(11) (2017) 7917-7934.

• Radii of starlikeness and convexity of a cross-product of Bessel functions [with N. Yağmur]. Ramanujan Journal 44(3) (2017) 493-519.

• Bounds for radii of starlikeness of some q-Bessel functions [with I. Aktaş]. Results in Mathematics 72(1) (2017) 947-963.

• Zeros of a cross-product of the Coulomb wave and Tricomi hypergeometric functions. Proceedings of the American Mathematical Society 145(4) (2017) 1643-1648.

• Bounds for the radii of univalence of some special functions [with I. Aktaş, N. Yağmur]. Mathematical Inequalities and Applications 20(3) (2017) 825-843.

• Turán type inequalities for Struve functions [with S. Ponnusamy, S. Singh]. Journal of Mathematical Analysis and Applications 445(1) (2017) 971-984.

• Bounds for the asymptotic order parameter of the stochastic Kuramoto model [with I. Mező]. Journal of Approximation Theory 217 (2017) 1-14.

• Properties of the Turánian of modified Bessel functions [with I. Mező]. Mathematical Inequalities and Applications 20(4) (2017) 991-1001.

• Geometric properties of some Lommel and Struve functions [with N. Yağmur]. Ramanujan Journal 42(2) (2017) 325-346.

• Monotonicity properties of the Bessel-Struve kernel [with S.R. Mondal, A. Swaminathan]. Bulletin of the Korean Mathematical Society  53(6) (2016) 1845-1856.

• Differential subordination and superordination results associated with the Wright function [with S. Kant, J.K. Prajapat]. Bulletin of the Iranian Mathematical Society 42(6) (2016) 1459-1477.

• Close-to-convexity of normalized Dini functions [with E. Deniz, N. Yağmur]. Mathematische Nachrichten 14-15(289) (2016) 1721-1726.

• Turán type inequalities for some Lommel functions of the first kind [with S. Koumandos]. Proceedings of the Edinburgh Mathematical Society 59 (2016) 569-579.

• Bounds for the product of modified Bessel functions [with D. Jankov Maširević, S. Ponnusamy, S. Singh]. Aequationes Mathematicae 90(4) (2016) 859-870.

• Radii of starlikeness of some special functions [with D.K. Dimitrov, H. Orhan, N. Yağmur]. Proceedings of the American Mathematical Society 144(8) (2016) 3355-3367.

• Modified Dini functions: monotonicity patterns and functional inequalities [with S. Ponnusamy, S. Singh]. Acta Mathematica Hungarica 149(1) (2016) 120-142.

• Starlikeness of a cross-product of Bessel functions [with H.A. Alkharsani, T.K. Pogány]. Journal of Mathematical Inequalities 10(3) (2016) 819-827.

• Turán type inequalities for confluent hypergeometric functions of the second kind [with S. Ponnusamy, S. Singh]. Studia Scientiarum Mathematicarum Hungarica 53(1) (2016) 74-92.

• The radius of alpha convexity of normalized Bessel functions of the first kind [with H. Orhan, R. Szász]. Computational Methods and Function Theory 16(1) (2016) 93-103.

• Ulam-Hyers stability of singular integral equations, via weakly Picard operators [with Sz. András, T.K. Pogány]. Fixed Point Theory 17(1) (2016) 21-36.

• Differential subordinations and superordinations for generalized Bessel functions [with H.A. Alkharsani, K.S. Nisar]. Bulletin of the Korean Mathematical Society 53(1) (2016) 127-138.

• Starlikeness of Bessel functions and their derivatives [with M. Çağlar, E. Deniz]. Mathematical Inequalities and Applications 19(2) (2016) 439-449.

• Turán type inequalities for general Bessel functions [with S. Ponnusamy, S. Singh]. Mathematical Inequalities and Applications 19(2) (2016) 709-719.

• Close-to-convexity of some special functions and their derivatives [with R. Szász]. Bulletin of the Malaysian Mathematical Sciences Society 39(1) (2016) 427-437.

• Radii of starlikeness and convexity of some q-Bessel functions [with D.K. Dimitrov, I. Mező]. Journal of Mathematical Analysis and Applications 435(1) (2016) 968-985.

• The radius of convexity of normalized Bessel functions [with R. Szász]. Analysis Mathematica 41(3) (2015) 141-151.

• Julia's lemma on the hyperbolic disk [with S. Ponnusamy, Cs. Varga]. Annales Academiae Scientiarum Fennicae Mathematica 40 (2015) 939-948.

• Extension of Karamata inequality for generalized inverse trigonometric functions [with T.K. Pogány]. Studia Universitatis Babeş-Bolyai Mathematica 60(3) (2015) 379-384.

• Convexity properties of generalized trigonometric and hyperbolic functions [with B.A. Bhayo, R. Klén]. Aequationes Mathematicae 89(3) (2015) 473-484.

• Differential subordinations involving generalized Bessel functions [with E. Deniz, M. Çağlar, H. Orhan]. Bulletin of the Malaysian Mathematical Sciences Society 38(3) (2015) 1255-1280.

• Turán type inequalities for regular Coulomb wave functions. Journal of Mathematical Analysis and Applications 430(1) (2015) 166-180.

• Bounds for Turánians of modified Bessel functions. Expositiones Mathematicae 33(2) (2015) 223-251.

• Turán type inequalities for generalized inverse trigonometric functions [with B.A. Bhayo, M. Vuorinen]. Filomat 29(2) (2015) 303-313.

• Bounds for Jaeger integrals [with T.K. Pogány, S. Ponnusamy, I. Rudas]. Journal of Mathematical Chemistry 53(5) (2015) 1257-1273.

• Van der Corput inequalities for Bessel functions [with A. Laforgia, T.K. Pogány]. Integral Transforms and Special Functions 26(1) (2015) 78-87.

• On an identity for zeros of Bessel functions [with D. Jankov Maširević, T.K. Pogány, R. Szász]. Journal of Mathematical Analysis and Applications 422(1) (2015) 27-36.

• Mapping properties of basic hypergeometric functions [with A. Swaminathan]. Journal of Classical Analysis 5(2) (2014) 115-128.

• The radius of convexity of normalized Bessel functions of the first kind [with R. Szász]. Analysis and Applications 12(5) (2014) 485-509.

• Functional inequalities for modified Struve functions II [with T.K. Pogány]. Mathematical Inequalities and Applications 17(4) (2014) 1387-1398.

• Landen inequalities for special functions. Proceedings of the American Mathematical Society 142(9) (2014) 3059-3066.

• Functional inequalities for modified Struve functions [with T.K. Pogány]. Proceedings of the Royal Society of Edinburgh Section A Mathematics 144(5) (2014) 891-904.

• Remarks on a parameter estimation for von Mises-Fisher distributions. Computational Statistics 29 (2014) 891-894.

• On a sum of modified Bessel functions [with T.K. Pogány]. Mediterranean Journal of Mathematics 11(2) (2014) 349-360.

• The radius of starlikeness of normalized Bessel functions of the first kind [with P.A. Kupán, R. Szász]. Proceedings of the American Mathematical Society 142(6) (2014) 2019-2025.

• Functional inequalities for the Bickley function [with T.K. Pogány]. Mathematical Inequalities and Applications 17(3) (2014) 989-1003.

• Turán determinants of Bessel functions [with T.K. Pogány]. Forum Mathematicum 26(1) (2014) 295-322.

• Functional inequalities for generalized inverse trigonometric and hyperbolic functions [with B.A. Bhayo, T.K. Pogány]. Journal of Mathematical Analysis and Applications 417 (2014) 244-259.

• The radius of univalence of the reciprocal of a product of two analytic functions [with M. Obradović, S. Ponnusamy]. Journal of Analysis 21 (2013) 1-19.

• Integral representations and summations of modified Struve function [with T.K. Pogány]. Acta Mathematica Hungarica 141(3) (2013) 254-281.

• Inequalities for the one-dimensional analogous of the Coulomb potential [with T.K. Pogány]. Acta Polytechnica Hungarica 10(7) (2013) 53-67.

• Integral representations of Dini series of Bessel functions [with D. Jankov, T.K. Pogány]. Integral Transforms and Special Functions 24(8) (2013) 628-635.

• Turán type inequalities for Tricomi confluent hypergeometric functions [with M.E.H. Ismail]. Constructive Approximation 37(2) (2013) 195-221.

• Differential inequalities and Bessel functions [with S. Ponnusamy]. Journal of Mathematical Analysis and Applications 400(2) (2013) 558-567.

• Turán type inequalities for q-hypergeometric functions [with K. Raghavendar, A. Swaminathan]. Journal of Approximation Theory 168 (2013) 69-79.

• On Turán type inequalities for modified Bessel functions [with S. Ponnusamy]. Proceedings of the American Mathematical Society 141(2) (2013) 523-532.

• Mills' ratio: Reciprocal convexity and functional inequalities. Acta Universitatis Sapientiae Mathematica 4(1) (2012) 26-35.

• Neumann series of Bessel functions [with D. Jankov, T.K. Pogány]. Integral Transforms and Special Functions 23(7) (2012) 529-538.  

• Turán type inequalities for Kratzel functions [with D. Jankov, T.K. Pogány]. Journal of Mathematical Analysis and Applications 388(2) (2012) 716-724.

• Integral representations for Neumann-type series of Bessel functions I_v, Y_v and K_v [with D. Jankov, T.K. Pogány]. Proceedings of the American Mathematical Society 140(3) (2012) 951-960. 

• Functional inequalities for the incomplete gamma function [with H. Alzer]. Journal of Mathematical Analysis and Applications 385(1) (2012) 167-178.

• On Kaluza's sign criterion for reciprocal power series [with J. Vesti, M. Vuorinen]. Annales Universitatis Mariae Curie-Sklodowska. Sectio A. Mathematica 65(2) (2011) 1-16.

• Functional inequalities for modified Bessel functions [with S. Ponnusamy, M. Vuorinen]. Expositiones Mathematicae 29(4) (2011) 399-414.

• The generalized Marcum Q-function: an orthogonal polynomial approach [with Sz. András, Y. Sun]. Acta Universitatis Sapientiae Mathematica 3(1) (2011) 60-76. 

• Integral representation of first kind Kapteyn series [with D. Jankov, T.K. Pogány]. Journal of Mathematical Physics 52 (2011) Art. 043518, pp. 7.

• Corrections to "Unified Laguerre polynomial-series-based distribution of small-scale fading envelopes'' [with Y. Sun, S. Zhou]. IEEE Transactions on Vehicular Technology 60(1) (2011) 347-349.

• Bounds for complete elliptic integrals of the first kind [with Sz. András]. Expositiones Mathematicae 28(4) (2010) 357-364.

• Turán type inequalities for some probability density functions. Studia Scientiarum Mathematicarum Hungarica 47(2) (2010) 175-189.

• Bounds for the generalized Marcum Q-function [with Y. Sun]. Applied Mathematics and Computation 217(5) (2010) 2238-2250.

• Powers of modified Bessel functions of the first kind. Applied Mathematics Letters 23(6) (2010) 722-724.

• Bounds for modified Bessel functions of the first and second kinds. Proceedings of the Edinburgh Mathematical Society 53(3) (2010) 575-599.

• Turán type inequalities for modified Bessel functions. Bulletin of the Australian Mathematical Society 82(2) (2010) 254-264.

• Starlikeness and convexity of generalized Bessel functions [with S. Ponnusamy]. Integral Transforms and Special Functions 21(9) (2010) 641-653.

• On the monotonicity, log-concavity and tight bounds of the generalized Marcum and Nuttall Q-functions [with Y. Sun, S. Zhou]. IEEE Transactions on Information Theory 56(3) (2010) 1166-1186.

• Univalence of integral operators involving Bessel functions [with B. Frasin]. Applied Mathematics Letters 23(4) (2010) 371-376.

• Geometrically concave univariate distributions. Journal of Mathematical Analysis and Applications 363(1) (2010) 182-196.

• Approximate average bit error probability for DQPSK over fading channels [with Y. Sun, M. Zhao, X. Xu, S. Zhou]. Electronics Letters 45(23) (2009) 1177-1179.

• Generalizations of Mitrinovic, Adamovic and Lazarevic's inequalities and their applications [with S. Wu]. Publicationes Mathematicae Debrecen 75(3-4) (2009) 447-458.

• Tight bounds for the generalized Marcum Q-function. Journal of Mathematical Analysis and Applications 360(1) (2009) 265-277.

• Monotonicity property of generalized and normalized Bessel functions of complex order [with Sz. András]. Complex Variables and Elliptic Equations 54(7) (2009) 689-696.

• New bounds for the generalized Marcum Q-function [with Y. Sun]. IEEE Transactions on Information Theory 55(7) (2009) 3091-3100.

• Sharp exponential Redheffer-type inequalities for Bessel functions [with S. Wu]. Publicationes Mathematicae Debrecen 74(3-4) (2009) 257-278.

• Sharp Jordan type inequalities for Bessel functions [with S. Wu]. Publicationes Mathematicae Debrecen 74(1-2) (2009) 107-126.

• Extensions of the generalized Wilker inequality to Bessel functions [with J. Sándor]. Journal of Mathematical Inequalities 2(3) (2008) 397-406.

• On a product of modified Bessel functions. Proceedings of the American Mathematical Society 137(1) (2009) 189-193.

• Inequalities for the generalized Marcum Q-function [with Y. Sun]. Applied Mathematics and Computation 203(1) (2008) 134-141.

• Functional inequalities involving Bessel and modified Bessel functions of the first kind. Expositiones Mathematicae 26(3) (2008) 279-293.

• Geometric properties of generalized Bessel functions. Publicationes Mathematicae Debrecen 73(1-2) (2008) 155-178.

• Jordan-type inequalities for generalized Bessel functions. Journal of Inequalities in Pure and Applied Mathematics 9(2) (2008) Art. 39, pp. 6.

• Properties of the probability density function of the non-central chi-squared distribution [with Sz. András]. Journal of Mathematical Analysis and Applications 346(2) (2008) 395-402.

• Turán type inequalities for hypergeometric functions. Proceedings of the American Mathematical Society 136(9) (2008) 3223-3229.

• A functional inequality for the survival function of the gamma distribution. Journal of Inequalities in Pure and Applied Mathematics 9(1) (2008) Art. 13, pp. 5.

• Mills' ratio: Monotonicity patterns and functional inequalities. Journal of Mathematical Analysis and Applications 340(2) (2008) 1362-1370.

• Extension of Oppenheim's problem to Bessel functions [with L. Zhu]. Journal of Inequalities and Applications. 2007 (2007) Art. 82038.

• Inequalities involving modified Bessel functions of the first kind II [with E. Neuman]. Journal of Mathematical Analysis and Applications 332(1) (2007) 256-271.

• Turán type inequalities for generalized complete elliptic integrals. Mathematische Zeitschrift 256(4) (2007) 895-911.

• Functional inequalities for Galué's generalized modified Bessel functions. Journal of Mathematical Inequalities 1(2) (2007) 183-193.

• Some inequalities involving generalized Bessel functions. Mathematical Inequalities and Applications 10(4) (2007) 827-842.

• Convexity of the zero-balanced Gaussian hypergeometric functions with respect to Hölder means. Journal of Inequalities in Pure and Applied Mathematics 8(2) (2007) Art. 40, pp. 9.

• Redheffer type inequality for Bessel functions. Journal of Inequalities in Pure and Applied Mathematics 8(1) (2007) Art. 11, pp. 6.

• Functional inequalities involving special functions II. Journal of Mathematical Analysis and Applications 327(2) (2007) 1202-1213.

• Grünbaum-type inequalities for special functions. Journal of Inequalities in Pure and Applied Mathematics 7(5) (2006) Art. 175, pp. 8.

• Bessel transforms and Hardy space of generalized Bessel functions. Mathematica 48(71)(2) (2006) 127-136.

• Functional inequalities involving special functions. Journal of Mathematical Analysis and Applications 319(2) (2006) 450-459.

• Geometric properties of generalized Bessel functions of complex order. Mathematica 48(71)(1) (2006) 13-18.

• Inequalities involving generalized Bessel functions [with E. Neuman]. Journal of Inequalities in Pure and Applied Mathematics 6(4) (2005) Art. 126, pp. 9.

• Landen-type inequality for Bessel functions. Computational Methods and Function Theory 5(2) (2005) 373-379.

• Univalent functions in simply connected domains. Libertas Mathematica 25 (2005) 97-103.

• A subclass of starlike functions. Mathematica 47(70)(1) (2005) 19-25.

• Applications of the admissible functions method for some differential equations. Pure Mathematics and Applications 13 (2002) 433-440.

Proceedings papers and other papers in volumes

• Bounds for an integral involving Whittaker functions of the second kind [with G.M. Assefa]. Proc. Inter. Symp. Appl. Comput. Intell. Inform., Timişoara (2025) 87-91.

• On Kapteyn-Kummer series' integral form [with T.K. Pogány, A. Szakál]. Proc. Inter. Symp. Appl. Comput. Intell. Inform., Timişoara (2016) 119-122.

• Incomplete Kratzel function model of leaky aquifer and alike functions [with T.K. Pogány, I. Rudas]. Proc. Inter. Symp. Appl. Comput. Intell. Inform., Timişoara (2015) 59-62.

• Bounds for the symmetric difference of generalized Marcum Q-functions [with T. Mészáros]. Proc. Inter. Symp. Appl. Comput. Intell. Inform., Timişoara (2015) 63-67.

• Properties of the product of modified Bessel functions [with T.K. Pogány]. Analytic Number Theory, Approximation Theory, and Special Functions (2014) 809-820.

• Alternating Mathieu series, Hilbert-Eisenstein series and their generalized Omega functions [with P.L. Butzer, T.K. Pogány]. Analytic Number Theory, Approximation Theory, and Special Functions (2014) 775-808.

• Monotonicity properties of some Dini functions [with T.K. Pogány, R. Szász]. Proc. Inter. Symp. Appl. Comput. Intell. Inform., Timişoara (2014) 323-326.

• New approximations for DQPSK transmission bit error rate [with Sz. András, J. Fodor]. Proc. Inter. Symp. Appl. Comput. Intell. Inform., Timişoara (2013) 73-77.

• Sampling Bessel functions and Bessel sampling [with D. Jankov Maširević, T.K. Pogány, A. Galántai]. Proc. Inter. Symp. Appl. Comput. Intell. Inform., Timişoara (2013) 79-84. 

Books

• Series of Bessel and Kummer type functions [with D. Jankov Maširević, T.K. Pogány], Lecture Notes in Mathematics, vol. 2207, Springer, Berlin, 2018.

• Generalized Bessel functions of the first kind, Lecture Notes in Mathematics, vol. 1994, Springer, Berlin, 2010.

• Statistics for economists [in Hungarian, with Sz. András], Státus, Miercurea-Ciuc [Csíkszereda], pp. 300, 2007.

Habilitation theses

• Radii of starlikeness and convexity of some special functions, Faculty of Mathematics and Computer Science, Babeş-Bolyai University, Cluj-Napoca, 2017.

• The generalized Marcum Q-function: inequalities, bounds and applications, Institute of Applied Mathematics, Óbuda University, Budapest, 2015. 

Ph.D. theses

• Turán type inequalities for some special functions, Institute of Mathematics, University of Debrecen, Debrecen, 2008.

• Generalized Bessel functions of the first kind, Faculty of Mathematics and Computer Science, Babeş-Bolyai University, Cluj-Napoca, 2008.