APA

Department of international economic and social affairs, . (1989). Levels and trends of contraceptive us as assessed in 1988. New York: United Nations.

Chicago

Department of international economic and social affairs, . 1989. Levels and trends of contraceptive us as assessed in 1988. New York: United Nations.

Harvard

Department of international economic and social affairs, . (1989). Levels and trends of contraceptive us as assessed in 1988. New York: United Nations.

MLA

Department of international economic and social affairs, . Levels and trends of contraceptive us as assessed in 1988. New York: United Nations. 1989.