Jones, David L. 1993. Cycads of the world. Australia: Reed Books.
A well-illustrated and very useful piece of work. Offers considerable information on cultivation and propagation of cycads. Highly recommended. However, its taxonomy is dated and many species are not included. These are not due to any shortcomings on the part of the author; rather, the decade of the 1990s was an extraordinary time in the cycad world, with many new species described and some substantial taxonomic changes (I should note that now, in 2002, this process is still very active and further major changes are likely). The new standard work is a superb book by Whitelock (2002).