Wilson, D. E., & Reeder, D. (2005). Halichoerus grypus subsp. grypus Fabricius 1791. The Johns Hopkins University Press.
Chicago Style (17th ed.) CitationWilson, Don E., and DeeAnn Reeder. Halichoerus Grypus Subsp. Grypus Fabricius 1791. The Johns Hopkins University Press, 2005.
MLA (9th ed.) CitationWilson, Don E., and DeeAnn Reeder. Halichoerus Grypus Subsp. Grypus Fabricius 1791. The Johns Hopkins University Press, 2005.
Warning: These citations may not always be 100% accurate.