APA (7th ed.) Citation

Hall, A. D., & Osterstock, H. C. (1940). The genus Tulipa. The Royal horticultural society.

Chicago Style (17th ed.) Citation

Hall, A. Daniel, and H. C. Osterstock. The Genus Tulipa. London: The Royal horticultural society, 1940.

MLA (9th ed.) Citation

Hall, A. Daniel, and H. C. Osterstock. The Genus Tulipa. The Royal horticultural society, 1940.

Warning: These citations may not always be 100% accurate.