Cita APA

Johnson, W. H. 1., & Steere, W. C. 1. (1974). The environmental challenge. New York: Holt, Rinehart and Winston, Inc..

Citación estilo Chicago

Johnson, Willis Hugh 1902-1994, y William Campell 1907- Steere. The Environmental Challenge. New York: Holt, Rinehart and Winston, Inc., 1974.

Cita MLA

Johnson, Willis Hugh 1902-1994, y William Campell 1907- Steere. The Environmental Challenge. New York: Holt, Rinehart and Winston, Inc., 1974.