Lial, M. L. (2005). Trigonometry. New York: Pearson Education, Inc.
Dyfyniad Arddull ChicagoLial, Margaret L. Trigonometry. New York: Pearson Education, Inc, 2005.
Dyfyniad MLALial, Margaret L. Trigonometry. New York: Pearson Education, Inc, 2005.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.