1.Istanbul Bilgi Universities, Istanbul, July 26-August 3, 2024.
2. Mersin University, Mersin, Turkey, December 13-17, 2023.
3. University of Manitoba, Canada, 21 Sept. 2018-21 June 2019 (C. Cowan).
4. University of Wyoming, USA, 15 June-1 August 2016 (G. D. Lyng).
5. Mathematisches Forschungsinstitut Oberwolfach (MFO), Oberwolfach, Germany, 1 July-14 August 2013.
6. University of Oulu, Finland, 4 August-28 August 2011 (P. A. Hasto).
7. University of Nis, Serbia, 8 June-19 June 2009 (V. Rakocevic).
8. University of Seville, Spain, 25 June-20 July 2008 (R. Espinola).
9. Royal Institute of Technology (KTH), Sweden, 5 April-1 September 2007 (H. Shahgholian).
10. Wolfgang Pauli Institute (WPI), Austria, 2 April-29 April 2005 (P. A. Markowich).
11. International Center for Theoretical Physics (ICTP), Italy, 21 April-9 May 1997.
12. ICTP, 15 April-3 May 1996.