Problems of Lower Cambrian paleontology and biostratigraphy of Siberia and Far East. Some brachiopods Inarticulata of Early and Middle Cambrian deposits of lower course of the Olenek River Basin. Rossiiskaya Akademiya Nauk Sibirskoe Otdelenie Trudy Instituta Geologii i Geofiziki, 49 1973: 69-80. 73 [Zoological Record Volume 115]