Dr. Michael Dzierzawa,
Université Fribourg
(April 1996)
Prof. Dr. Peter S. Riseborough,
Department of Applied Mathematics and Physics, Polytechnic University, New York
(July/August 1996)
Prof. Dr. Anupam Garg,
Department of Physics,
Northwestern University, Evanston
(August 1996)
Prof. Dr. Peter S. Riseborough,
Department of Applied Mathematics and Physics, Polytechnic University, New York
(June 1997)
Prof. Dr. Daniel I. Khomskii,
Solid State Physics Laboratory,
University of Groningen
(February 1998)
Prof. Dr. Peter S. Riseborough,
Department of Applied Mathematics and Physics, Polytechnic University, New York
(July/August 1998)
Prof. Dr. Marten den Boer,
Hunter College, City University, New York
(July 1998)
Prof. Dr. Peter S. Riseborough,
Department of Applied Mathematics and Physics, Polytechnic University, New York
(June/July 1999)
Dr. Vanik Mkrtchian,
Academy of Science, Armenia
(November/December 1999)