Cita APA (7th ed.)

Friedel, R. A culture of improvement. The MIT Press.

Cita Chicago (17th ed.)

Friedel, Robert. A Culture of Improvement. Cambridge: The MIT Press.

Cita MLA (9th ed.)

Friedel, Robert. A Culture of Improvement. The MIT Press.

Atenció: Aquestes cites poden no estar 100% correctes.