1. A molecular phylogenetic study of Graptopetalum (Crassulaceae) based on ETS, ITS, rpl16, and trnL-F nucleotide sequences;Acevedo-Rosas;Am. J. Bot.,2004
2. Ribosomal ITS sequences and plant phylogenetic inference;Álvarez;Mol. Phylogenet. Evol.,2003
3. Bemerkungen über die Arten der Gattung Circaea Tourn;Ascherson;Bot. Zeitung (Berlin),1870
4. The evolution of flowering plants;Axelrod,1960
5. Axelrod, D.I., 1980. The Turlock Lake Flora. In: Contributions of the Neogene Paleobotany of Central California. Geological Sciences, vol. 121. University of California Publications, pp. 81–120.