Stefan Cohn-Vossen taught at the University of Cologne from 1930-1933.

• List of publications of S. Cohn-Vossen
• Wikipedia entry on S. Cohn-Vossen
• On the works of S. E. Cohn-Vossen, Aleksandrov, A.D.,
   Uspehi Matem. Nauk (N.S.) 2, (1947). no. 3(19), 107--141
• Article by J.J.O'Connor and E.F.Robertson on S.Cohn-Vossen
• A brief essay of S. Cohn-Vossen on Differential Geometry
• A speech of S. Cohn-Vossen at the beginning of S. Cohn-Vossen’s USSR career
• Articles in local newspapers: Kölner Stadt-Anzeiger vom 20.10.2014, 

He was also a composer. Here are two of his pieces.

• Piano piece written by S. Cohn-Vossen
• Fuge for two violins and piano by S. Cohn-Vossen 

In 2014 a seminar room was dedicated to his memory.

• Invitation
• Beamer presentation as pdf
• Speech of the rector Prof. T. Küpper
• Speech of Prof. B. Kawohl   (German)  (English)
• Speech of the son Richard Cohn-Vossen

• The colloquium lecture of Prof. V. Remmert on  forms of remigration
   was published in the Mathematical Intelligencer
   (Volker R. Remmert: Forms of Remigration,
   Émigré Jewish Mathematicians and Germany in the Immediate Postwar Period,
   The Mathematical Intelligencer March 2015, Volume 37, issue 1, pp 30-40).
   With permission of Springer Science+Business Media.