APA

Catholic Church, . (1903). The great encyclical letters of Pope Leo XIII. New York: Benziger Brothers.

Chicago

Catholic Church, . 1903. The great encyclical letters of Pope Leo XIII. New York: Benziger Brothers.

Harvard

Catholic Church, . (1903). The great encyclical letters of Pope Leo XIII. New York: Benziger Brothers.

MLA

Catholic Church, . The great encyclical letters of Pope Leo XIII. New York: Benziger Brothers. 1903.