Scott Richardson; Harriet Allen (2000). Washington State Recovery Plan for the Sea Otter(PDF) (Report). Olympia, Washington: Washington Department of Fish and Wildlife. Archived from the original(PDF) on March 23, 2012. Retrieved July 3, 2011.
Scott Richardson; Harriet Allen (2000). Washington State Recovery Plan for the Sea Otter(PDF) (Report). Olympia, Washington: Washington Department of Fish and Wildlife. Archived from the original(PDF) on March 23, 2012. Retrieved July 3, 2011.