(in addition to numerous invited lectures at conferences, etc.)
1970 Three months at the University of Ife, Nigeria.
1974 One month at International Centre for Theoretical Physics, Trieste, Italy.
1975 One month at Max-Planck Centre for Molecular Beam Research, Göttingen, Germany.
1976 Three months at the Indian Institute of Science, Bangalore.
1980 Six weeks at the Les Houches Summer School, France
1980-81 Kramers Professor of Physics at the University of Utrecht, The Netherlands.
1980 Troisième Cycle de la Suisse Romande Lecturer in Theoretical Physics at Geneva and Lausanne, Switzerland.
1981 Three weeks at the Les Houches Summer School, France.
1983 One month visiting Fellow at Australian National University, Canberra (Dept. of Applied Mathematics).
1983 One month Erskine Visiting Fellow at University of Canterbury at Christchurch, New Zealand (Dept. of Electrical Engineering).
1985 One month Visiting Lecturer at Institut Physique Nucléaire, Orsay, France.
1985 One month Visiting Fellow at California Institute of Technology, USA.
1986-97 Fellowship at Weizmann Institute, Rehovot, Israel (annual visits, one month each)
1988 One Month Visiting Lecturer at Department of Mathematics, University of Nice, France.
1989 Two weeks at Les Houches summer School, France.
1989 Two weeks as Director of School on Geometric Phases, ICTP Trieste, Italy
1989 Visiting Fellow, Technion, Haifa, Israel
1999 Two months as Lorentz Professor, Leiden, The Netherlands
2004 Lecturing at Summer School on Vortices at Cargese (Corsica)
2006 Lecturing at School on Wave Propagation at Cuernavaca (Mexico)
2007 One month as Solvay Professor, Brussels
2008 One month as Distinguished Visiting Fellow, ICTP Trieste
2014 Ten undergraduate lectures at IIT Kharagpur