Biostrategraphic zoning and trilobites of the Upper Cambrian and Lower Ordovician of the Northwestern Siberian Platform - Rozova, Antonina V. (Balkema, 1984)
EST: Biostratigrafija i trilobity verchnego kembrija i nižnego ordovika severo-zapada Sibirskoj Platformy <engl.>. - Aus d. Russ. übers.