1. An almost human grey parrot;Amsler;Avic. Mag.,1947
2. Baldwin , J. M. 1914 Deferred imitation in West African grey parrots 536
3. The vocal ability of the Indian Hill mynah, Gracula religiosa;Bertram;Anim. Behav.,1970
4. Tool-using by birds and other behavior;Boswall;Avic. Mag.,1977
5. Über das Unterscheidungsvermögen unbenannter Anzahlen bei Papageien;Braun;Z. Tierpsychol.,1952