Nikitin & Popov 1984. [Brachiopods of the Bestamak and Sargaldak Suit (Middle Ordovician).] Bandaletov, S.M.[Ed]. [Brachiopods and biostratigraphy of Middle and Upper Ordovician of the Chingiz Range.], Nauka, Alma Ata, 1984: 6-125. Chapter pagination: 126-166