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]
Gestation lasts about 11 months, at the end of which a calf about 6-7 m long and weighing 1-1,5 metric tons is born.