Koneva & Popov 1983. [Certain new lingulids from the Upper Cambrian and Lower Ordovician of Malij Karatau.] 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: 112-124