Keywords: TanygnathusEverettiKeulemans.jpg Tanygnathus everetti Tanygnathus sumatranus everetti Blue-backed Parrot ssp Catalogue of the Birds in the British Museum Volume 20 1891 Creator John Gerrard Keulemans PD-old-100 John Gerrard Keulemans Catalogue of the Birds in the British Museum Tanygnathus sumatranus |