Hudson-Lamb, Gavin Charles; Schoeman, Johan P.; Hooijberg, Emma Henriette; Heinrich, Sonja K.; Tordiffe, Adrian Stephen Wolferstan(AOSIS OpenJournals, 2016-02-26)
Van Sonsbeek, Gerda R.; Van der Kolk, Johannes H.; Van Leeuwen, Johannes P.T.M.; Everts, Hendrik; Marais, Johan; Schaftenaar, Willem(American Association of Zoo Veterinarians, 2013-09)