APA (7th ed.) Citation

Maritain, J., & Watkin, E. I. (1930). An introduction to philosophy. Sheed & Ward.

Chicago Style (17th ed.) Citation

Maritain, Jacques, and E. I. Watkin. An Introduction to Philosophy. London: Sheed & Ward, 1930.

MLA (8th ed.) Citation

Maritain, Jacques, and E. I. Watkin. An Introduction to Philosophy. Sheed & Ward, 1930.