Russian avant-garde @ Ludwig

I have always loved the Russian avant-garde.  When I visited Koeln's Museum Ludwig in July, I was impressed by its broad collection.

Kazimir Malevich at Ludwig, 2011:

Ilja Tchaschnik at Ludwig, 2011:

Alexander Rodchenko at Ludwig, 2011:

Another edition of Rodchenko's spatial construction Square In A Square in the last picture was shown at Berlinische Galerie in Berlin.