Perrin, W.F.; Würsig, B.; Thewissen, J.G.M. (2009). Encyclopedia of marine mammals. Second edition. Academic Press: London. ISBN 978-0-12-373553-9. xxix, 1316 pp. (look up in IMIS) [details]
Adult lengths range from about 2,5 m to about 3,8 m, varying by georgaphic location. Body size appears to vary inversely with water temperature in many parts of the world, but not the eastern Pacific.