Cita APA (7a ed.)

Orleans, J. S. (1926). A Study of the Nature of Difficulty: Thesis. Columbia University in the City of New York.

Cita Chicago Style (17a ed.)

Orleans, Jacob S. A Study of the Nature of Difficulty: Thesis. New York City: Columbia University in the City of New York, 1926.

Cita MLA (9a ed.)

Orleans, Jacob S. A Study of the Nature of Difficulty: Thesis. Columbia University in the City of New York, 1926.