APA (7th ed.) Citation

Boff, L., Boff, C., & Burns, P. (1989). Introducing liberation theology. Burns & Oates.

Chicago Style (17th ed.) Citation

Boff, Leonardo, Clodovis Boff, and Paul Burns. Introducing Liberation Theology. Kent [England]: Burns & Oates, 1989.

MLA (9th ed.) Citation

Boff, Leonardo, et al. Introducing Liberation Theology. Burns & Oates, 1989.