ELECTRONICS LETTERS, vol. 34, no. 10, page. 964 - 966, 1998-05-14
ELECTRONICS LETTERS, vol. 34, no. 3, page. 312 - 313, 1998-02-05
NEURAL, PARALLEL & SCIENTIFIC COMPUTATIONS, vol. 6, no. 1, page. 121 - 142, 1998-01