Korsch 1938: OCLC2952443 (all editions) According to WorldCat there has been a publication in 1936 (London); but we may suppose that's a mistake. Reissue 1963 at Internet Archive.
Michael Buckmiller: Marxismus als Realität. In: Jahrbuch Arbeiterbewegung, Nr. 1, Über Karl Korsch, Claudio Pozzoli (Hrsg.), Fischer Taschenbuch-Verlag, Frankfurt am Main 1973, S. 55 OCLC4847844
Korsch 1938: OCLC2952443 (all editions) According to WorldCat there has been a publication in 1936 (London); but we may suppose that's a mistake. Reissue 1963 at Internet Archive.