Cita APA (7th ed.)
Schumacher, E. A Guide for the Perplexed. Harper Perennial.
Cita Chicago (17th ed.)
Schumacher, E.F. A Guide for the Perplexed. Nueva York, EUA: Harper Perennial.
Cita MLA (9th ed.)
Schumacher, E.F. A Guide for the Perplexed. Harper Perennial.
Atenció: Aquestes cites poden no estar 100% correctes.