APA (7th ed.) Citation

Falconi, C. (1967). The Popes in the twentieth century: From Pius X to John XXIII. Little, Brown.

Chicago Style (17th ed.) Citation

Falconi, Carlo. The Popes in the Twentieth Century: From Pius X to John XXIII. Boston: Little, Brown, 1967.

MLA (9th ed.) Citation

Falconi, Carlo. The Popes in the Twentieth Century: From Pius X to John XXIII. Little, Brown, 1967.