Taxon - Odkazy a literatura
Paleobiology Database [9542]
Paleobiology Database [https://paleobiodb.org/] [jako Beretra Stephenson, 1941]
Datum citace: 24. prosinec 2015
The Interim Register of Marine and Nonmarine Genera [1380753]
Rees, T. (compiler): The Interim Register of Marine and Nonmarine Genera [https://www.irmng.org] [jako Beretra Stephenson, 1941]
Datum citace: 30. listopad 2019