APA (7th ed.) Citation

Sendak, M. (1990). One was Johnny: A counting book. HarperCollins Publishers.

Chicago Style (17th ed.) Citation

Sendak, Maurice. One Was Johnny: A Counting Book. New York: HarperCollins Publishers, 1990.

MLA (9th ed.) Citation

Sendak, Maurice. One Was Johnny: A Counting Book. HarperCollins Publishers, 1990.

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