"The Biology of the Cycads," Knut J. Norstog & Trevor J. Nicholls. Cornell University Press, 1997.

Contains an in-depth section on prehistory of the cycads, in addition to being an excellent and up-to-date reference on the living cycads. A "must-have" book for anyone interested in cycads.

"Dinosaurs, A Global View," Sylvia & Stephen Czerkas. Mallard Press, New York, 1991.

This is a comprehensive and thought provoking work on Mesozoic environments with excellent illustrations.

"Gymnosperms, Structure and Evolution," Charles J. Chamberlain, Univ. of Chicago Press, 1935

A classic work on the evolution of the Cycadales.

"Descriptions of New Species of Tertiary Cycads, with a Review of those previously recorded," Authur Hollick, Bulletin of the Torry Club, Vol. 59, No. 4, 1932.

Another classic review of fossil cycads.

"Indian Cycads," Rita Singh & Willie Tang, Editors,
Special Issue of The Cycad Newsletter, Vol. XVI No. 2, 1993

An interesting collection of papers availalble from The Cycad Society.

"Global Environment and Diversification of Plants through Geologic Time: Proceedings of the International Conference, Allahabad, India," Pant, D.D., editor, Vedams Books International, New Delhi, India,

A very diverse series of modern papers dealing with fossil plants.

"Petrified Wood," Frank J. Daniels, Western Colorado Publishing Company, 1998

A modern work on an ancient subject.