Williams, A. (1965). Superfamily Orthacea. pp. 307-328. In: R. C. Moore (ed.). Treatise on invertebrate paleontology, Part H, Brachiopoda, Volume 1. The Geological Society of America, Boulder, CO & University of Kansas Press, Lawrence, KS, 521 pp.
482145
Williams, A.
1965
Superfamily Orthacea. pp. 307-328. In: R. C. Moore (ed.)
Treatise on invertebrate paleontology, Part H, Brachiopoda, Volume 1
The Geological Society of America, Boulder, CO & University of Kansas Press, Lawrence, KS, 521 pp.