Grant, V. (2003), "Incongruence between cladistic and taxonomic systems", American Journal of Botany, 90 (9): 1263–70, doi:10.3732/ajb.90.9.1263, PMID21659226
Grant, V. (2003), "Incongruence between cladistic and taxonomic systems", American Journal of Botany, 90 (9): 1263–70, doi:10.3732/ajb.90.9.1263, PMID21659226