Cita APA (7th ed.)
Pieper, J. (1960). As virtudes fundamentais. Editorial Aster.
Cita Chicago (17th ed.)
Pieper, Josef. As Virtudes Fundamentais. Lisboa: Editorial Aster, 1960.
Cita MLA (9th ed.)
Pieper, Josef. As Virtudes Fundamentais. Editorial Aster, 1960.
Atenció: Aquestes cites poden no estar 100% correctes.