APA

Passelecq G, Suchecky B, . (1997). The Hidden Encyclical of Pius XI. New York; San Diego; London: Harcourt Brace & Company.

Chicago

Passelecq G, Suchecky B, . 1997. The Hidden Encyclical of Pius XI. New York; San Diego; London: Harcourt Brace & Company.

Harvard

Passelecq G, Suchecky B, . (1997). The Hidden Encyclical of Pius XI. New York; San Diego; London: Harcourt Brace & Company.

MLA

Passelecq G, Suchecky B, . The Hidden Encyclical of Pius XI. New York; San Diego; London: Harcourt Brace & Company. 1997.