Hayes, P. (1936). Pope Pius XI. National Council of Catholic Men.
Cita Chicago Style (17a ed.)Hayes, Patrick. Pope Pius XI. Washington, D.C.: National Council of Catholic Men, 1936.
Cita MLA (8a ed.)Hayes, Patrick. Pope Pius XI. National Council of Catholic Men, 1936.
Precaución: Estas citas no son 100% exactas.