APA (7th ed.) Citation

Pius XI, P., Pizzardo, G., Bertram, A., & Segura y Sáenz, P. (1937). The Pope and Catholic action. Catholic Truth Society.

Chicago Style (17th ed.) Citation

Pius XI, Pope, Giuseppe Pizzardo, Adolf Bertram, and Pedro Segura y Sáenz. The Pope and Catholic Action. London: Catholic Truth Society, 1937.

MLA (8th ed.) Citation

Pius XI, Pope, et al. The Pope and Catholic Action. Catholic Truth Society, 1937.