↑ Ogg, J.G.; Ogg, G.; Gradstein, F.M. (2016). A Concise Geologic Time Scale: 2016. Amsterdam: Elsevier. m/s. 115. ISBN978-0-444-63771-0.
↑ Murchison, R.I.; de Verneuil, E.; von Keyserling, A. (1842). On the Geological Structure of the Central and Southern Regions of Russia in Europe, and of the Ural Mountains. London: Richard and John E. Taylor. m/s. 14. Permian System. (Zechstein of Germany — Magnesian limestone of England)—Some introductory remarks explain why the authors have ventured to use a new name in reference to a group of rocks which, as a whole, they consider to be on the parallel of the Zechstein of Germany and the magnesian limestone of England. They do so, not merely because a portion of deposits has long been known by the name "grits of Perm", but because, being enormously developed in the governments of Perm and Orenburg, they there assume a great variety of lithological features ...
↑ Murchison, R.I.; de Verneuil, E.; von Keyserling, A. (1845). Geology of Russia in Europe and the Ural Mountains. Vol. 1: Geology. London: John Murray. m/s. 138–139. ...Convincing ourselves in the field, that these strata were so distinguished as to constitute a system, connected with the carboniferous rocks on the one hand, and independent of the Trias on the other, we ventured to designate them by a geographical term, derived from the ancient kingdom of Permia, within and around whose precincts the necessary evidences had been obtained. ... For these reasons, then, we were led to abandon both the German and British nomenclature, and to prefer a geographical name, taken from the region in which the beds are loaded with fossils of an independent and intermediary character; and where the order of superposition is clear, the lower strata of the group being seen to rest upon the Carboniferous rocks.
↑ Verneuil, E. (1842). "Correspondance et communications". Bulletin de la Société Géologique de France. 13: 11–14. Le nom de Système Permien, nom dérivé de l'ancien royaume de Permie, aujourd'hui gouvernement de Perm, donc ce dépôt occupe une large part, semblerait assez lui convener ...
