APA

Institute for the Comparative Study of Political Systems (U.S.), . (1968). Puerto Rico election factbook, November 5, 1968. Washington, D.C: The Institute.

Chicago

Institute for the Comparative Study of Political Systems (U.S.), . 1968. Puerto Rico election factbook, November 5, 1968. Washington, D.C: The Institute.

Harvard

Institute for the Comparative Study of Political Systems (U.S.), . (1968). Puerto Rico election factbook, November 5, 1968. Washington, D.C: The Institute.

MLA

Institute for the Comparative Study of Political Systems (U.S.), . Puerto Rico election factbook, November 5, 1968. Washington, D.C: The Institute. 1968.