• [Wiki] http://en.wikipedia.org/wiki/Phoca_vitulina.
• [AnAge] http://genomics.senescence.info/species/Phoca_vitulina.
• [KovaLyde] http://www.npolar.no/en/species/harbour-seal.html.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.
• [KovaLavi1986] Kovacs, K. M. and Lavigne, D. M. (1986). Maternal investment and neonatal growth in phocid seals. Journal of Animal Ecology, 55:1035--1051.
• [MarkBjor1989] Markussen, N. H., Bjørge, A., and ØRitsland, N. A. (1989). Growth in harbour seals (Phoca vitulina) on the Norwegian coast. Journal of Zoology, 219(3):433--440. doi:10.1111/j.1469-7998.1989.tb02591.x.