Some of the usual suspects at the Amsterdam Meeting of Flux, Charge and Topology (July 1999)
With Fidel Schaposnik in Urbana
Many of the usual suspects at the ICMT Meeting on Topological Phases in Condensed Matter (Urbana, October 2008)
Many more of the usual suspects at the FradkinFest (Stanford, December 2010)
Participants at the workshop on Geometrical Degrees of Freedom in Topological Phases at the Banff International Research Station (Banff, Alberta, Canada), August 21-26 (2016).