https://libcom.org/article/karl-marx-man-and-fighter-boris-nicolaievsky-and-otto-maenchen-helfen
Karl Marx: man and fighter - Boris Nicolaievsky and Otto Maenchen-Helfen | libcom.org
Part of the series of biographies of Karl Marx. 1933 biography of Karl Marx by Otto Maenchen-Helfen and Boris Ivanovich Nicolaevsky (1887-1966), who was a...
otto maenchen helfenkarl marxboris nicolaievsky
https://archive.org/details/bub_gb_CrUdgzSICxcC/page/4/mode/2up
The world of the Huns; studies in their history and culture : Maenchen-Helfen, Otto : Free...
An extensive study of the origins and culture of the mysterious Huns and the civilizations affected by their invasions