Goodman, N. (1972). Problems and projects. Bobbs-Merrill.
Cita Chicago (17th ed.)Goodman, Nelson. Problems and Projects. Indianapolis: Bobbs-Merrill, 1972.
Cita MLA (9th ed.)Goodman, Nelson. Problems and Projects. Bobbs-Merrill, 1972.
Atenció: Aquestes cites poden no estar 100% correctes.