251. Transition to agriculture and first state presence: A global analysis Bookmark Format Single study
252. Transnational Social Movement Organization Dataset, 1953-2003 Bookmark Format Series - completed
253. Trends in International Mathematics and Science Study (TIMSS) (1995+) Bookmark Format Series - ongoing
256. United Nations Surveys of Crime Trends and Operations of Criminal Justice Systems (1970+) Bookmark Format Series - ongoing
257. United States Citizenship, Involvement, Democracy (CID) Survey, 2006 Bookmark Format Single study