APA (7th ed.) Citation

Carretto, C., Hancock, R. M., & Illich, I. (1972). Letters from the desert. Orbis Books.

Chicago Style (17th ed.) Citation

Carretto, Carlo, Rose Mary Hancock, and Ivan Illich. Letters from the Desert. Maryknoll: Orbis Books, 1972.

MLA (9th ed.) Citation

Carretto, Carlo, et al. Letters from the Desert. Orbis Books, 1972.