Leo XIII. (1998). Encyclical letter: Libertas Praestantissimum of the Supreme Pontiff Pope Leo XIII on human liberty, June 20, 1888 (Angelus Press Edition, February 1998.). Angelus Press.
Citazione stile Chigago Style (17a edizione)Leo XIII. Encyclical Letter: Libertas Praestantissimum of the Supreme Pontiff Pope Leo XIII on Human Liberty, June 20, 1888. Angelus Press Edition, February 1998. Kansas City: Angelus Press, 1998.
Citatione MLA (9a ed.)Leo XIII. Encyclical Letter: Libertas Praestantissimum of the Supreme Pontiff Pope Leo XIII on Human Liberty, June 20, 1888. Angelus Press Edition, February 1998. Angelus Press, 1998.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.