BioStor
 | Notes on the families and genera of tortoises (Testudinata), and on the characters afforded by the study of their skulls J E Gray (1869) Proceedings of the Zoological Society of London 1869: 165-225 |
 | November 1, 1870 Newton (1870) Proceedings of The Zoological Society of London 1870: 663-747 |
 | June 6, 1811 George Busk (1871) Proceedings of The Zoological Society of London 1871: 506-543 |