Certo, S. C. (2006). Supervision: Concepts and skill-building. Boston: McGraw-Hill.
Dyfyniad Arddull ChicagoCerto, Samuel C. Supervision: Concepts and Skill-building. Boston: McGraw-Hill, 2006.
Dyfyniad MLACerto, Samuel C. Supervision: Concepts and Skill-building. Boston: McGraw-Hill, 2006.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.