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Dyfyniad Arddull ChicagoVoight, Ralph Claude. Invitation to Learning: The Learning Center Handbook. Washington: Acropolis Books, 1971.
Dyfyniad MLAVoight, Ralph Claude. Invitation to Learning: The Learning Center Handbook. Acropolis Books, 1971.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.