 | J. Stern , Ecole Normale Supérieure , Paris, France,
May 1 - June 1, 1990 |
| M. Boffa , Universite de l'Etat a Mons, , Belgium,
May 1 - June 1, 1990 |
| R. Chuaqui , University Catholica de Chile, Santiago, Chile,
May 1 - June 1, 1990 |
| D. Follesdal , Institute for Advanced Study, Berlin, Germany,
May 1 - June 1, 1990 |
| I. Hacking , University of Toronto, Toronto, Canada,
May 1 - June 1, 1990 |
| D. Kurepa , Belgrade University, Belgrade, Yugoslavia,
May 1 - June 1, 1990 |
| J. Moravscick , Stanford University, Stanford, USA,
May 1 - June 1, 1990 |
| A. Edalat , Imperial College London, London, UK,
May 1 - June 1, 1990 |
| V. Kosygin , Moscow State University, Moscow, Russia,
Jan. 1, 1990 |
|
