APA

United States, . (19961999). World population profile. Washington, D.C: U.S. Agency for International Development, Bureau for Global Programs, Field Support, and Research, Office of Population.

Chicago

United States, . 19961999. World population profile. Washington, D.C: U.S. Agency for International Development, Bureau for Global Programs, Field Support, and Research, Office of Population.

Harvard

United States, . (19961999). World population profile. Washington, D.C: U.S. Agency for International Development, Bureau for Global Programs, Field Support, and Research, Office of Population.

MLA

United States, . World population profile. Washington, D.C: U.S. Agency for International Development, Bureau for Global Programs, Field Support, and Research, Office of Population. 19961999.