Daniel T. Ksepka and Julia A. Clarke (2012). "A new stem parrot from the Green River Formation and the complex evolution of the grasping foot in Pan-Psittaciformes". Journal of Vertebrate Paleontology. 32 (2): 395–406. doi:10.1080/02724634.2012.641704. S2CID85308803.
Gerald Mayr; Andrew C. Kitchener (2023). "The Vastanavidae and Messelasturidae (Aves) from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK)". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 307 (2): 113–139. doi:10.1127/njgpa/2023/1119. S2CID257598310.
Daniel T. Ksepka and Julia A. Clarke (2012). "A new stem parrot from the Green River Formation and the complex evolution of the grasping foot in Pan-Psittaciformes". Journal of Vertebrate Paleontology. 32 (2): 395–406. doi:10.1080/02724634.2012.641704. S2CID85308803.
Gerald Mayr; Andrew C. Kitchener (2023). "The Vastanavidae and Messelasturidae (Aves) from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK)". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 307 (2): 113–139. doi:10.1127/njgpa/2023/1119. S2CID257598310.