APA

Pío XII P., . (1940). The Pope speaks. New York: Harcourt, Brace and Co.

Chicago

Pío XII Papa, . 1940. The Pope speaks. New York: Harcourt, Brace and Co.

Harvard

Pío XII P., . (1940). The Pope speaks. New York: Harcourt, Brace and Co.

MLA

Pío XII Papa, . The Pope speaks. New York: Harcourt, Brace and Co. 1940.