1995 February--April: George Mason University, Fairfax, Va, USA and University at College Park, in Maryland (USA).

1996 August:  George Mason University, Fairfax, Va, USA.

1997 Jenuary--May:  George Mason University, Fairfax, Va, USA.

1999 September 1--10:  State University of Gent, Belgium.

2001 February 22-- March 10: George Mason University, Fairfax, Va, USA.

2002 February 18-- March 5: State University of Gent, Belgium.

2002 June  2--10:  State University of Ghent, Belgium.

2002 November 17--24:  Charles University of Prague, Cech Republic.

2003 March--April:  George Mason University, Fairfax, Va, USA.

2004 February 23--27:  State University of Gent, Belgium.

2004 May 16--27:  George Mason University, Fairfax, Va, USA.

2005 August 3-31:  George Mason University, Fairfax, Va, USA.

2006 April 3-13:  George Mason University, Fairfax, Va, USA.

2006 November 20 -26:  Charles University of Prague, Cech Republic.

2007 April--May:   Chapman University, Orange, CA, USA.

2007 September 6--7:  State University of Gent, Belgium.

2008 July 17--August 29:  Chapman University, Orange, CA, USA.

2008 November 9--14: State University of Gent, Belgium.

2009 August 2--7:  State University of Gent, Belgium.

2009  October 8-- November 28:  Chapman University, Orange, CA, USA.

2010 April 2--8: Charles University of Prague, Czech Republic.

2010  October 15--22: Instituto Politecnico Nacional  Mexico City, Mexico.

2010 October 22 --November 20:  Chapman University, Orange, CA, USA.