Pitman, R.L. & Ballance, L.T. & Mesnick, S.I. & Chivers, S.J. (2001)
Killer Whale Predation on Sperm Whales: Observations and Implications. Marine Mammal Science, 17(3), 494–507
DOI: 10.1111/j.1748-7692.2001.tb01000.x