| 2014 | Yale, Bristol, UCL |
| 2013 | Cambridge, Boston College-MIT |
| 2012 | Rochester, McMaster, Northwestern |
| 2011 | Berkeley, MSRI |
| 2010 | Princeton U, Institute for Advanced Study, UBC |
| 2009 | Paris VI, Institut Henri Poincaré,Paris Sud, Nancy, Cambridge, Bordeaux |
| 2008 | U Wisconsin, Emory |
| 2007 | Institute for Advanced Study, NYU, Rutgers, Princeton U, Columbia |
| 2006 | Queens |
| 2005 | Stanford, Berkeley |
| 2004 | Columbia/CUNY/NYU, NYU/Princeton, Harvard, Cambridge, Amherst |
| 2003 | Toronto |
| 2001 | Montreal Joint Colloquium, Furman |
| 2000 | Clemson |
| 1999 | Montreal Joint Colloquium, Georgia Tech |
| 1998 | Arizona. |
| 1997 | Shandong U, Acad. Sinica (Beijing), NorthWestern U (Xian), Guangzhou, McGill |
| 1996 | Colorado |
| 1995 | North Carolina State, York, Delaware |
| 1994 | Michigan (Ann Arbor, x5), Concordia (Montreal), Western Ontario (London), Toronto, Urbana-Champaign, Ohio State |
| 1993 | Isaac Newton Institute, Villadollid (x2) Complutense (Madrid), Sheffield, Oxford, Autonoma (Madrid). |
| 1992 | Columbia (New York City), Princeton, Georgia Tech. |
| 1991 | Institute for Advanced Study. |
| 1990 | Institute for Advanced Study (x2), Pace, Stanford, S.U.N.Y. (Buffalo), UBC, Maryland. |
| 1989 | Florida, Queen's, Rochester, UBC, Urbana--Champaign, Toronto, Wisconsin, Georgia, Purkyne, Slovak Acad. Sci. (Bratislava), Hungarian Acad. Sci. (Budapest), Institute for Advanced Study. |
| 1988 | Waterloo, Berkeley, Rochester. |
| 1987 | Laval, Carleton, Queen's |
| 1986 | Carleton (Ottawa), Waterloo. |