G. W.  Rothwell, Mapes, G., Stockey, R. A., Hilton, J., and Bateman, R. M., ?Descent with modification, transformational series, and phylogenetic analyses to infer the evolution of modern conifer families, in Abstracts GSA Annual Meeting Portland?, Geological Society of America Abstracts with Program, vol. 41, no. 7, p. 563, 2009.