Transactions of the fourth World Congress of Sociology : Milan and Sresa, 8-15 Sept. 1959 ; general theme: Society and sociological knowledge =Actes du quatrieme Congres mondial de sociologie ; Milan and Stresa, 8-15 Sept. 1959 ; La societe et la connaissance sociologique. Vol.1, Sociology in its social context (International Sociological Association, 1959)