APA (7th ed.) Citation

Baynes, P., & Perry, P. (1947). Question Mark: The story of an enquiring young person. P. Perry.

Chicago Style (17th ed.) Citation

Baynes, Pauline, and Powell Perry. Question Mark: The Story of an Enquiring Young Person. [London?]: P. Perry, 1947.

MLA (9th ed.) Citation

Baynes, Pauline, and Powell Perry. Question Mark: The Story of an Enquiring Young Person. P. Perry, 1947.