PRIVATE ENTERPRISE IN EASTERN EUROPE: THE NON-AGRICULTURAL PRIVATE SECTOR IN POLAND AND THE GDR, 1945-83 by Anders Aslund. New York: St. Martin's Press, 1984. 320 pp., $29.95. COLLECTIVE FARMS WHICH WORK? by Nigel Swain. New York: Cambridge University Press, 1985. 320 pp., $39.50. LABOUR AND LEISURE IN THE SOVIET UNION: THE CONFLICT BETWEEN PUBLIC AND PRIVATE DECISION-MAKING IN A PLANNED ECONOMY by William Moskoff. New York: St. Martin's Press, 1984. 225 pp., $27.50. COERCION AND CONTROL IN COMMUNIST SOCIETY: THE VISIBLE HAND OF BUREAUCRACY by M. Hirszowicz. New York: St. Martin's Press, 1985. 256 pp., $27.50.