Chernykh, V. V.; Chuvashov, B. I.; Davydov, V. I.; Schmitz, M.; Snyder, W. S. (2006). Usolka section (southern Urals, Russia): a potential candidate for GSSP to define the base of the Gzhelian Stage in the global chronostratigraphic scale. Geologija. 49(2): 205-217.
Chernykh, V. V.; Chuvashov, B. I.; Davydov, V. I.; Schmitz, M.; Snyder, W. S.
2006
Usolka section (southern Urals, Russia): a potential candidate for GSSP to define the base of the Gzhelian Stage in the global chronostratigraphic scale