1966Acanthograptus impar sp. nov. — Bulman et Rickards, pp. 32-36, fig. 23-25
Selection of related publications
Bulman, O. M. B., Rickards, R. B. 1966.
A Revision of Wiman's Dendroid and Tuboid Graptolites.Bulletin of the Geological Institutions of the University of Uppsala43,
6-8,1-72.