Wilhelms, F. T. (1973). Supervision in a new key. Association for Supervision and Curriculum Development.
Cita Chicago (17th ed.)Wilhelms, Fred T. Supervision in a New Key. Washington: Association for Supervision and Curriculum Development, 1973.
Cita MLA (9th ed.)Wilhelms, Fred T. Supervision in a New Key. Association for Supervision and Curriculum Development, 1973.
Atenció: Aquestes cites poden no estar 100% correctes.