Nov 2015 – Massachusetts Institute of Technology.
Nov 2016
2014 Universidade de Coimbra, Department of Mathematics, one week.
2012 Technische Universität Chemnitz, Department of Mathematics, one week.
2011 Univerza v Ljubljani, Department of Mathematics, three days.
2011 Universität zu Köln, Department of Computer Science, three days.
2010 Ruprecht-Karls-Universität Heidelberg, Department of Computer Science, two weeks.
