APA

National Academy of Sciences (United States), . (1972). The earth and human affairs. New York: Canfield Press.

Chicago

National Academy of Sciences (United States), . 1972. The earth and human affairs. New York: Canfield Press.

Harvard

National Academy of Sciences (United States), . (1972). The earth and human affairs. New York: Canfield Press.

MLA

National Academy of Sciences (United States), . The earth and human affairs. New York: Canfield Press. 1972.