APA (7th ed.) Citation

Alston, A. H. G., Jermy, A. C., & Rankin, J. M. (1981). The genus Selaginella in tropical South America. British Museum (Natural History).

Chicago Style (17th ed.) Citation

Alston, A. H. G., A. C. Jermy, and J. M. Rankin. The Genus Selaginella in Tropical South America. London: British Museum (Natural History), 1981.

MLA (9th ed.) Citation

Alston, A. H. G., et al. The Genus Selaginella in Tropical South America. British Museum (Natural History), 1981.