APA (7th ed.) Citation

Du Bois, W. P. (1947). Twenty-one balloons. Viking.

Chicago Style (17th ed.) Citation

Du Bois, William Pene. Twenty-one Balloons. [S.l.]: Viking, 1947.

MLA (9th ed.) Citation

Du Bois, William Pene. Twenty-one Balloons. Viking, 1947.

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