basis of recordMead, J. G.; Brownell, R. L. Jr. (2005). Cetacea. <em>In Wilson, D.E. & D.M. Reeder (eds). Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), Johns Hopkins University Press, 2,142 pp.</em> 723--743., available online athttp://www.bucknell.edu/msw3/[details]