Cady, M. E. (1929). Principles of true science. College Press.
Cita Chicago (17th ed.)Cady, Marion E. Principles of True Science. College Press, 1929.
Cita MLA (9th ed.)Cady, Marion E. Principles of True Science. College Press, 1929.
Atenció: Aquestes cites poden no estar 100% correctes.