1- 28 September 1995 - 27 September 1996, ICTP, Trieste, Italy as Diploma student.

2- 30 September 1997 - 21 November 1997, Goethe-Institute, Bremen, Germany.

3- 21 November 1997 - 30 September 1999, Kiel University, Germany as visiting researcher under the supervision of Prof. Dr. M. Brokate.

4- 1 October 1999 - 26 November 1999 Munich University of Technology, Germany as visiting researcher under the supervision of Prof. Dr. M. Brokate.

5- 3 July 2004 - 3 September 2004, ICTP, Trieste, Italy as Regular Associate.

6- 12 July 2005 - 9 September 2005, ICTP, Trieste, Italy as Regular Associate.