Marxism: Change & Constancy[br]Bertram D. Wolfe, [i]Marxism, 100 Years in the Life of a Doctrine[/i][br]Milorad M. Drachkovitch (ed.), [i]Marxism in the Modern World[/i][br]Robert C. Tucker and Stephen F. Cohen (eds.) [i]The Great Purge Trial[/i]