On the External Morphology of the Stems of Calamites, with a Revision of the British Species of Calamophloios and Dictyocalamites of Upper Carboniferous Age
E. A. Newell Arbert, F. W. Lawfield. "On the External Morphology of the Stems of Calamites, with a Revision of the British Species of Calamophloios and Dictyocalamites of Upper Carboniferous Age." Journal of the Linnean Society of London Botany 44.300 (1920) 507-530