2 literature references for Virganthura crassa (Barnard, 1925):

Author: Schotte, M., B.F. Kensley, and S. Shilling.
Year: 1995
Title: nwards). World list of Marine, Freshwater and Terrestrial Crustacea Isopoda. National Museum of Natural History Smithsonian Institution: Washington D.C., USA.
Author: Barnard, K.H.
Year: 1925
Title: A Revision of the Family Anthuridae (Crustacea Isopoda), with Remarks on certain Morphological Peculiarities. Journ. Limn. Soc (London) (Zool.) 36: 109-160.