DiMichele, William A., Chaney, Dan S., Nelson, W. J., Lucas, Spencer G., Looy, C. V., Quick, K., and Jun, Wang. 2007. "A low diversity, seasonal tropical landscape dominated by conifers and peltasperms: Early Permian Abo Formation, New Mexico." Review of Palaeobotany and Palynology. 145:249–273.