Cita APA (7th ed.)

Graham, W. F. (1975). Angels: God's secret agents. Doubleday.

Cita Chicago (17th ed.)

Graham, William Franklin. Angels: God's Secret Agents. Garden City, N.Y: Doubleday, 1975.

Cita MLA (9th ed.)

Graham, William Franklin. Angels: God's Secret Agents. Doubleday, 1975.