APA
Feinsinger, P., Colwell, R. K., Terborgh, J., & Chaplin, S. B. (1979). Elevation and the morphology, flight energetics, and foraging ecology of tropical hummingbirds. The American Naturalist, 113, 481–497.
Chicago/Turabian
Feinsinger, Peter, Robert K Colwell, John Terborgh, and Susan Budd Chaplin. “Elevation and the Morphology, Flight Energetics, and Foraging Ecology of Tropical Hummingbirds.” The American Naturalist 113 (1979): 481–497.
MLA
Feinsinger, Peter, et al. “Elevation and the Morphology, Flight Energetics, and Foraging Ecology of Tropical Hummingbirds.” The American Naturalist, vol. 113, University of Chicago Press, 1979, pp. 481–97.