Hall, Ailsa J.; Watkins, John; Hiby, Lex (16 July 1996). "The impact of the 1993 Braer oil spill on grey seals in Shetland". Science of the Total Environment. Marine Mammals And The Marine Environment. 186 (1–2): 119–125. doi:10.1016/0048-9697(96)05090-5. PMID8685704.
Hall, Ailsa J.; Watkins, John; Hiby, Lex (16 July 1996). "The impact of the 1993 Braer oil spill on grey seals in Shetland". Science of the Total Environment. Marine Mammals And The Marine Environment. 186 (1–2): 119–125. doi:10.1016/0048-9697(96)05090-5. PMID8685704.