Stanich, Nicholas; Gar W. Rothwell; Ruth A. Stockey. Phylogenetic diversification of Equisetum (Equisetales) inferrred from Lower Cretaceous species of British Columbia, Canada.. American Journal of Botany. 2009, 96 (7): 1289–1299. PMID 21628278. doi:10.3732/ajb.0800381.
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Stanich, Nicholas; Gar W. Rothwell; Ruth A. Stockey. Phylogenetic diversification of Equisetum (Equisetales) inferrred from Lower Cretaceous species of British Columbia, Canada.. American Journal of Botany. 2009, 96 (7): 1289–1299. PMID 21628278. doi:10.3732/ajb.0800381.