Constructivist-Congress at Weimar : 1922

from left to right / from back to front :
Lucia & László Moholy-Nagy
Max & Lotte Burchartz, Peter Röhl, Hans Vogel Alfred Kémény
Alexa Röhl Bernhard Sturtzkopf
El Lissitzky, Nelly & Theo van Doesburg
Werner Graeff, Nini Smit, Harry Scheibe,
Cornelis van Eesteren, Hans Richter, Tristan Tzara, Hans Arp