Heide-Jørgensen MP, KL Laidre , ML Burt, DL Borchers, RG Hansen, M Rasmussen and S Fossette (2009) Abundance of narwhals (Monodon monoceros) in Greenland. NAMMCO/SC/16-JCNB/SWG/2009-JWG/20 Udgivet 12.03.2019