Criteria for a finite group to be Abelian or Cyclic. (pdf)
Criteria for some special types of two-variable polynomials over a field to be irreducible. (pdf)
On Maximal Subgroups of the Additive Group (Q, +). (pdf)
Analysis and Numerical Analysis
Applications of optimal error bounds for some generalized two-step iterative processes in Banach spaces (with Tan-Phuc Nguyen, Tien-Khai Nguyen, Cong-Duy-Nguyen Nguyen and Trung-Hieu Huynh). [link]
The Runge-kutta methods for numerical analysis. (pdf)