Leatherwood, S., R. R. Reeves, W. F. Perrin and W. E. Evans. (1982). Whales, dolphins, and porpoises of the eastern North Pacific and adjacent Arctic waters. A guide to their identification. NOAA Technical Report NMFS Circular 444. 245pp.
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Leatherwood, S.; Reeves, R. R.; Perrin, W. F.; Evans, W. E.
1982
Whales, dolphins, and porpoises of the eastern North Pacific and adjacent Arctic waters. A guide to their identification