Cita APA

Ewel, J. J., & Whitmore, J. L. (1973). The ecological life zones of Puerto Rico and the U.S. Virgin islands. Rio Piedras: Institute of Tropical Forestry.

Citación estilo Chicago

Ewel, J. J., y J. L. Whitmore. The Ecological Life Zones of Puerto Rico and the U.S. Virgin Islands. Rio Piedras: Institute of Tropical Forestry, 1973.

Cita MLA

Ewel, J. J., y J. L. Whitmore. The Ecological Life Zones of Puerto Rico and the U.S. Virgin Islands. Rio Piedras: Institute of Tropical Forestry, 1973.