L.  Watson, Dallwitz, M. J., Gibbs, A. J., y Pankhurst, R. J., «Automated taxonomic descriptions», in Prospects in Systematics, D. L.  Hawksworth, Ed. Oxford: Clarendon Press, 1988, pp. 293-304.

C.  Patterson, «The impact of evolutinary theories on systematics», in Prospects in Systematics, D. L.  Hawksworth, Ed. Oxford: Clarendon Press, 1988, pp. 59-91.