Sergiovanni, T. J. (1990). Value-added leadership: How to get extraordinary performance in schools. Harcourt Brace Jovanovich, HBJ Leadership.
Dyfyniad Arddull ChicagoSergiovanni, Thomas J. Value-added Leadership: How to Get Extraordinary Performance in Schools. San Diego: Harcourt Brace Jovanovich, HBJ Leadership, 1990.
Dyfyniad MLASergiovanni, Thomas J. Value-added Leadership: How to Get Extraordinary Performance in Schools. Harcourt Brace Jovanovich, HBJ Leadership, 1990.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.