Cita APA

Tracy, G. R., Friedl, A. E., & Trapp, H. E. (1979). Modern physical science. Holt.

Citación estilo Chicago

Tracy, George R., Alfred E. Friedl, and Harry E. Trapp. Modern Physical Science. New York: Holt, 1979.

Cita MLA

Tracy, George R., et al. Modern Physical Science. Holt, 1979.