APA (7th ed.) Citation

Cavanna, B. (1955). The first book of sea shells. F. Watts.

Chicago Style (17th ed.) Citation

Cavanna, Betty. The First Book of Sea Shells. New York: F. Watts, 1955.

MLA (9th ed.) Citation

Cavanna, Betty. The First Book of Sea Shells. F. Watts, 1955.