APA (7th ed.) Citation

Cribb, P., & Green, P. (1997). The genus Cypripedium. Timber Press.

Chicago Style (17th ed.) Citation

Cribb, Phillip, and Peter Green. The Genus Cypripedium. Portland, Or.: Timber Press, 1997.

MLA (9th ed.) Citation

Cribb, Phillip, and Peter Green. The Genus Cypripedium. Timber Press, 1997.