Attributes / relations provided by
♦ ¹McMeans, Bailey C., et al. "The role of Greenland sharks (Somniosus microcephalus) in an Arctic ecosystem: assessed via stable isotopes and fatty acids." Marine Biology 160.5 (2013): 1223+. Academic OneFile. Web. 14 July 2014.
♦ ²Food Web Relationships of Northern Puget Sound and the Strait of Juan de Fuca : a Synthesis of the Available Knowledge, Charles A. Simenstad, Bruce S. Miller, Carl F. Nyblade, Kathleen Thornburgh, and Lewis J. Bledsoe, EPA-600 7-29-259 September 1979
♦ ³Phocoena phocoena, David E. Gaskin, Peter W. Arnold, and Barbara A. Blair, MAMMALIAN SPECIES No. 42, pp. 1-8 (1974)