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Dyfyniad Arddull ChicagoÖpik, Helgi. The Physiology of Flowering Plants. Cambridge, UK: Cambridge University Press, 2005.
Dyfyniad MLAÖpik, Helgi. The Physiology of Flowering Plants. Cambridge, UK: Cambridge University Press, 2005.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.