1. S. E. Kleĭnenberg, A. V. Yablokov, V. M. Bel’kovich, and M. N. Tarasevich, Beluga Whale. A Monographic Study of the Species (Nauka, Moscow, 1964) [in Russian].
2. T. A. Jefferson, S. Leatherwood, and M. A. Webber, FAO Species Identification Guide: Marine Mammals of the World (FAO and UNEP, Rome, 1993).
3. V. M. Bel’kovich and M. N. Shchekotov, The Beluga Whale: Natural Behavior and Bioacoustics (Woods Hole Oceanographic Institution, Woods Hole, 1993).
4. B. L. Sjare and T. G. Smith, Can. J. Zool. 64, 407 (1986).
5. B. L. Sjare and T. G. Smith, Can. J. Zool. 64, 2824 (1986).