Cita APA (7th ed.)
Guardini, R. Freedom, grace and destinity. Pantheon Books.
Cita Chicago (17th ed.)
Guardini, Romano. Freedom, Grace and Destinity. Nueva York, EUA: Pantheon Books.
Cita MLA (9th ed.)
Guardini, Romano. Freedom, Grace and Destinity. Pantheon Books.
Atenció: Aquestes cites poden no estar 100% correctes.