Hanspeter Ryser:
Ecole Polytechnique Fédérale
Hanspeter Ryser:
Ecole Polytechnique Fédérale
Hanspeter Ryser:
Ecole Polytechnique Fédérale
Hanspeter Ryser:
Ebenen - Streetart
Hanspeter Ryser:
uni Lausanne
Hanspeter Ryser:
railway station