References
- Yakovleff , N. 1903 . Fauna of the upper Portion of the Palæozoic Deposits of the Donetz Basin . Transactions of the Geological Committee , news series
- Duerden , J.E. 1902 . On the Relationships of the Rugosa to the living Zoantheæ . Ann. & Mag. Nat. Hist. , May : 381 – 381 .