APA (7th ed.) Citation

Castle, I., Duncan, R. L., & Duncan, W. (1958). Castles in the air. Doubleday.

Chicago Style (17th ed.) Citation

Castle, Irene, Robert L. Duncan, and Wanda Duncan. Castles in the Air. Garden City, N.Y.: Doubleday, 1958.

MLA (9th ed.) Citation

Castle, Irene, et al. Castles in the Air. Doubleday, 1958.