Artikeltje in 'Periodiek', Fysisch-Mathematische Faculteitsvereniging RUG, Nov./Dec. 2005 pp. 14 -17: An account of a climbing tour in the Bernese Alps
Mathematics in India: An account of a trip
to India and Sikkim
August 2013: Col du Galibier, France
July 2013: Col du Grand St. Bernard, Swiss/Italy
November 2011, Kurama, Japan.
April 2009. Iguazu '09: horse riding near Buenos Aires, Argentina.
April 2009. Iguazu '09: with Robert, Femke and Jasper at the Iguazu waterfalls in Brazil.
November, 2008. Visit to the A-bomb dome in Hiroshima.
September, 2008. With Eva Zerz and Jochen Trumpf in the Negev near SdeBoker, Israel
July 2008. Hiking near Blacksburg, Virginia, USA, during the MTNS Conference at Virginia Tech.
November, 2007. Making a cycling tour through Tokyo
November, 2007. A dinner party in Nagoya
August 14, 2001. On the summit ridge of Grunegghorn (right), approaching the
Gross Grunhorn (left)
August 14, 2001. On the summit of the Gross Grunhorn
August 15, 2001. On the summit of the Finsteraarhorn
August 16, 2001. On the summit of the Gross Fiescherhorn. In the picture on
the left the Finsteraarhorn,
on the right the Gross Grunhorn
August 1998. On the summit of Piz Roseg
August 1998. On the summit of Piz Palu
Participants of the workshop for Jan Willems' 60th Birthday
Jan Willems together with his former and present Ph.D. Students