Gerald Mayr. Old World fossil record of modern-type hummingbirds. „Science”. 304 (5672), s. 861–864, 2004. DOI: 10.1126/science.1096856. (ang.).
Gerald Mayr. New specimens of the early Oligocene Old World hummingbird Eurotrochilus inexpectatus. „Journal of Ornithology”. 148 (1), s. 105–111, 2007. DOI: 10.1007/s10336-006-0108-y. (ang.).
Antoine Louchart, Nicolas Tourment, Julie Carrier, Thierry Roux, Cécile Mourer-Chauviré. Hummingbird with modern feathering: an exceptionally well-preserved Oligocene fossil from southern France. „Naturwissenschaften”. 95 (2), s. 171–175, 2007. DOI: 10.1007/s00114-007-0309-0. (ang.).
Zygmunt Bocheński, Zbigniew M. Bocheński. An Old World hummingbird from the Oligocene: a new fossil from Polish Carpathians. „Journal of Ornithology”. 149 (2), s. 211–216, 2008. DOI: 10.1007/s10336-007-0261-y. (ang.).
Gerald Mayr, Norbert Micklich. New specimens of the avian taxa Eurotrochilus (Trochilidae) and Palaeotodus (Todidae) from the early Oligocene of Germany. „Paläontologische Zeitschrift”. 84 (3), s. 387–395, 2010. DOI: 10.1007/s12542-009-0047-z. (ang.).
