APA (7th ed.) Citation

Régamey, P., & Pontifex, M. (1960). What is an angel? Hawthorn books.

Chicago Style (17th ed.) Citation

Régamey, Pie-Raymond, and Mark Pontifex. What Is an Angel? New York: Hawthorn books, 1960.

MLA (9th ed.) Citation

Régamey, Pie-Raymond, and Mark Pontifex. What Is an Angel? Hawthorn books, 1960.

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