APA (7th ed.) Citation

British Delphinium Society. (1956). The British Delphinium Society's year book. British Delphinium Society.

Chicago Style (17th ed.) Citation

British Delphinium Society. The British Delphinium Society's Year Book. [London, England?]: British Delphinium Society, 1956.

MLA (9th ed.) Citation

British Delphinium Society. The British Delphinium Society's Year Book. British Delphinium Society, 1956.

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