Fordyce, E.; Perrin, W.F. (2025). World Cetacea Database. Physeteridae. Accessed through: Land J. van der (ed). (2008) UNESCO-IOC Register of Marine Organisms (URMO) at: https://www.marinespecies.org/urmo/aphia.php?p=taxdetails&id=136985 on 2025-06-24