World communism. New introduction by Aron R. Paperbacks for the Study of Communism and Marxismby F. Borkenau;Communist totalitarianism: keys to the Soviet systemby B. D. Wolfe; L. Schapiro;The realities of world communism. University Extension Series on Public Issueby W. Petersen;Communism in Europe. Continuity, change, and the Sino-Soviet dispute. Volume 2. Center for International Studies - Massachusetts Institute of Technology. Studies in International Communismby W. E. Griffith