This paper is unavailable as a self archived post print. Sheng-Uei Guan and Kiruthika Ramanathan, “A Lateral Symmetry Approach to Percentage Based Hybrid Pattern (PHP) Training”, 241-273, Vol. 16, No. 3, Journal of Intelligent Systems, 2007 If you wish to obtain a copy of this article please visit http://people.brunel.ac.uk/~hssrjis/ or email one of the authors for a personal copy: Steven.Guan@brunel.ac.uk Brunel University Research Archive (BURA) http://bura.brunel.ac.uk