Borrel, Assumpción, and Petter J.H. Reijnders. “Summary of Temporal Trends in Pollutant Levels Observed in Marine Mammals”. J. Cetacean Res. Manage. (January 1, 1999): 149–155. Accessed December 7, 2021. https://journal.iwc.int/index.php/jcrm/article/view/265.