Cooper, G. A. (1952). Unusual Specimens of the Brachiopod Family Isogrammidae. <em>Journal of Paleontology.</em> 26(1): 113-119.[details] Available for editors
original descriptionCooper, G. A. (1952). Unusual Specimens of the Brachiopod Family Isogrammidae. <em>Journal of Paleontology.</em> 26(1): 113-119.[details] Available for editors