When doing some follow up investigation after a visit to Volklingen I came across a report of an ICOMOS conference in Moscow in 2006 which might be useful to those forum members interested in 20C Architecture.
The report's title is a rather strange
"The Soviet heritage and European Modernism" but its subject ranges rather wider, covering 20th Century architecture on the List (or potentially so in the case of many Russian structures) with particular reference to Russia and Germany - as such it contains articles on Volklingen, Zollverein, Berlin Modernism, Bauhaus,
The articles are in a mixture of German, English and (particularly in the case of the Russian buildings) in Russian
http://www.international.icomos.org/risk/2007/pdf/Soviet_Heritage_FULL_100dpi.pdf