Fox, A. D. & Nuttall, M. (red.) (2005). Divers or Loons. I M. Nuttall (red.), Encyclopedia of the Arctic, Volume 1: A-F Index (s. 497-499). Frank Cass Publishers.
Fox, A. D. & Nuttall, M. (red.) (2005). Eider. I M. Nuttall (red.), Encyclopedia of the Arctic, Volume 1: A-F Index (s. 547-549). Frank Cass Publishers.