APA (7th ed.) Citation

Waddell, M., & Firth, B. (1988). Can't you sleep, little bear? Walker.

Chicago Style (17th ed.) Citation

Waddell, Martin, and Barbara Firth. Can't You Sleep, Little Bear? London: Walker, 1988.

MLA (9th ed.) Citation

Waddell, Martin, and Barbara Firth. Can't You Sleep, Little Bear? Walker, 1988.