Harley, Heidi E. (13 November 2007). "Whistle discrimination and categorization by the Atlantic bottlenose dolphin (Tursiops truncatus): A review of the signature whistle framework and a perceptual test". Behavioural Processes. 77 (2). Elsevier: 243–268. doi:10.1016/j.beproc.2007.11.002. PMID18178338.
Walkley, Sarah; Zapetis, Maria; Lyn, Heidi (2018). "Vocalizations of North American river otters ( Lontra canadensis ) in two human care populations". The Journal of the Acoustical Society of America. 144 (3_Supplement): 1954. Bibcode:2018ASAJ..144.1954W. doi:10.1121/1.5068543.
Walkley, Sarah; Zapetis, Maria; Lyn, Heidi (2018). "Vocalizations of North American river otters ( Lontra canadensis ) in two human care populations". The Journal of the Acoustical Society of America. 144 (3_Supplement): 1954. Bibcode:2018ASAJ..144.1954W. doi:10.1121/1.5068543.
Harley, Heidi E. (13 November 2007). "Whistle discrimination and categorization by the Atlantic bottlenose dolphin (Tursiops truncatus): A review of the signature whistle framework and a perceptual test". Behavioural Processes. 77 (2). Elsevier: 243–268. doi:10.1016/j.beproc.2007.11.002. PMID18178338.