Cita APA (7a ed.)

Shepard, P., & McKinley, D. (1971). Environmental essays on the planet as home. Houghton-Mifflin.

Cita Chicago Style (17a ed.)

Shepard, Paul, y Daniel McKinley. Environmental Essays on the Planet as Home. Boston: Houghton-Mifflin, 1971.

Cita MLA (9a ed.)

Shepard, Paul, y Daniel McKinley. Environmental Essays on the Planet as Home. Houghton-Mifflin, 1971.