Kliushnikov, M. N., 1958. Transactions of the Institute of Geological Sciences, series Stratigraphy and Paleontology; published by the Ukrainian SSR Academy of Sciences, Kiev, 13-453 .
New Species-Group Names:
- asper Kliushnikov, 1958. p. 424. pl. 46 fig. 5.
- elegans Kliushnikov, 1958. p. 423. pl. 46 fig. 4.