found:Mammal species of the world (MSW) via WWW, Sept. 26, 2001(Halichoerus grypus, common name: Gray seal; original name: Phoca grypus)
found:ITIS Database search, Sept. 26, 2001(Halichoerus grypus; vernacular name: gray seal)
found:Web. 3(gray seal)
found:Encarta world Eng. dict.(gray seal)
found:Thomas, L. Assessment of population consequences of harvest strategies for the northwest Atlantic grey seal population, ©2009:p. 1 (grey seals)
found:World register of marine species, Jan. 31, 2019(Halichoerus grypus (Fabricius, 1791). Orig. name: Phoca grypus Fabricius, 1791. Synonymised names: Phoca grypus Fabricius, 1791. English vernacular: grey seal, gray seal)
found:IUCN red list, 2018-2, via WWW, Jan. 31, 2019(Grey Seal, Halichoerus grypus. Synonym: Phoca grypus Fabricius, 1791. Common names: Grey Seal, Gray Seal, Horsehead Seal, Long-nosed Seal)
