Cita APA

Halsey, W. D. (1981). Collier's Encyclopedia V.20. Mac Millan Company.

Citación estilo Chicago

Halsey, William D. Collier's Encyclopedia V.20. New York: Mac Millan Company, 1981.

Cita MLA

Halsey, William D. Collier's Encyclopedia V.20. Mac Millan Company, 1981.