Ivshin & Ergaliev 1983. [Certain trilobites of the Upper Cambrian and Lower Ordovician of the Bolshoi Karatau and Ulutau.] Apollonov, M.K.; Bandaletov, S.M.; Ivshin, N.K.[Eds]. The Lower Palaeozoic stratigraphy and palaeontology of Kazakhstan., Nauka, Leningrad, 1983: 1-176. Chapter pagination: 35-66