Cita APA (7th ed.)
Ruggiero, G. d. (1921). Modern philosophy. George Allen & Unwin.
Cita Chicago (17th ed.)
Ruggiero, Guido de. Modern Philosophy. London: George Allen & Unwin, 1921.
Cita MLA (9th ed.)
Ruggiero, Guido de. Modern Philosophy. George Allen & Unwin, 1921.
Atenció: Aquestes cites poden no estar 100% correctes.