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Dyfyniad Arddull ChicagoFRI. FRI Annual Report 1997. New Zealand: Forest Research institute Ltd, 1997.
Dyfyniad MLAFRI. FRI Annual Report 1997. Forest Research institute Ltd, 1997.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.