Political Grouping in the Czechoslovak Reform Movement. By Vladimir V. Kusin. Political and Social Processes in Eastern Europe Series. New York: Columbia University Press, 1972. xii, 224 pp. $11.00. - Public Opinion Polling in Czechoslovakia, 1968-69: Results and Analysis of Surveys Conducted During the Dubcek Era. By Jaroslaw A. Piekalkiewics. Foreword by Barry Bede. New York: Praeger Publishers, 1972. xxix, 357 pp. $18.50. - Social Change and Stratification in Postwar Czechoslovakia. By Jaroslav Krejčí. Political and Social Processes in Eastern Europe Series. New York: Columbia University Press, 1972. xvi, 207 pp. $11.00.