John U, Fensome RA, Medlin LK (2003) The Application of a Molecular Clock Based on Molecular Sequences and the Fossil Record to Explain Biogeographic Distributions Within the Alexandrium tamarense ‘‘Species Complex’’ (Dinophyceae). Mol Biol Evol, 20 (7): 1015-1027
Montresor, M., John, U., Beran, A. & Medlin, L.K. (2004). Alexandrium tamutum sp. nov. (Dinophyceae): a new nontoxic species in the genus Alexandrium. J Phycol 40: 398-411