Hayes, P. (1936). Pope Pius XI. National Council of Catholic Men.
Chicago Style aipamenaHayes, Patrick. Pope Pius XI. Washington, D.C.: National Council of Catholic Men, 1936.
MLA aipamenaHayes, Patrick. Pope Pius XI. National Council of Catholic Men, 1936.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.