Electronics Letters
Electronics Letters > 1989 > 25 > 16 > 1098 - 1100
Electronics Letters > 1991 > 27 > 2 > 151 - 153
Electronics Letters > 1991 > 27 > 8 > 679 - 680
Electronics Letters > 1992 > 28 > 3 > 295 - 296
Electronics Letters > 1992 > 28 > 25 > 2329 - 2330