Minutes of meetings, correspondence and lists of members of the ISA Council, Research Council and Executive Committee 1956-1994; documents concerning World Congresses of Sociology including correspondence, preparatory papers, lists of the participants, summaries of the papers presented, papers presented and final reports 1950-1998; correspondence with organizational and individual members, correspondence with UNESCO, United Nations, European authorities, International Institute of Sociology and World Health Organization 1938-1995; reports on activities of the ISA 1950-1989; reports and minutes of the Constituent Congress in Oslo 1949; statutes 1949-1986; financial reports 1951-1975; documents concerning housing 1972-1977, members including correspondence, statistics, membership files and lists of individual and collective members 1950-1994, projects, conferences and seminars in which ISA was involved 1960-1992, the Publication Committee 1966-1994, the Membership and Finance Committee 1967-1993 and the Research Committees 1965-1998; documentation concerning ISA 1968-1995. Correspondence by Margaret S. Archer (University of Warwick), member of the editorial board of Current Sociology . The Journal of the International Sociological Association 1973-1986; correspondence with publishers Mouton and SAGE 1971-1989. The first accrual of 2021 contains documents concerning the meetings of the Research Committee 28 on Social Stratification, 1986-2015, inv.no 992. Newsletters from the Research Committee that formed part of the accrual were added to inv.no. 809 and 897 depending on the year. Doubles were removed. The second accrual of 2021 contains documents concerning the meetings of what would eventually become the Research Committee on Economy and Society, 1970-1979, inv. no. 993.