APA (7th ed.) Citation

Norgaard, E., & Hildesheim, E. (1971). The book of balloons. Crown.

Chicago Style (17th ed.) Citation

Norgaard, Erik, and Erik Hildesheim. The Book of Balloons. New York: Crown, 1971.

MLA (9th ed.) Citation

Norgaard, Erik, and Erik Hildesheim. The Book of Balloons. Crown, 1971.

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