EBSEES: 2 hits for Hagen, Mark von

The European Bibliography of Slavic and East European Studies (EBSEES) collects books, journal articles, reviews and dissertations from Eastern Europe (former countries of Eastern Bloc) which were published in Belgium, Germany, Finland, France, Great Britain, the Netherlands, Austria and Switzerland from 1991 to 2007. The segment "Literature" and "Culture" of the European Bibliography of Slavic and East European Studies contains 18.000 bibliographic entries (from the total asset of 85.000). More information can be found here.

Your search for Hagen, Mark von provides 2 hits
1	Soldiers in the proletarian dictatorship: the Red Army and the Soviet Socialist State, 1917-1930 Von Hagen, Mark, Ithaca, NY, London, Cornell University Press, 1990, xviii+375 p
2	"From Russia to Soviet Union to Eurasia: a view from New York ten years after the end of the Soviet Union", in: Klio ohne Fesseln? Historiographie im östlichen Europa nach dem Zusammenbruch des Kommunismus, hrsg. v. Alojz Ivanišević, Andreas Kappeler, Walter Lukan und Arnold Suppan Hagen, Mark von, in: Österreichische Osthefte 44, 1/2, 2002, pp. 45-60

The European Bibliography of Slavic and East European Studies (EBSEES) - 1991-2007

Soldiers in the proletarian dictatorship: the Red Army and the Soviet Socialist State, 1917-1930

"From Russia to Soviet Union to Eurasia: a view from New York ten years after the end of the Soviet Union", in: Klio ohne Fesseln? Historiographie im östlichen Europa nach dem Zusammenbruch des Kommunismus, hrsg. v. Alojz Ivanišević, Andreas Kappeler, Walter Lukan und Arnold Suppan