Electronics Letters
Electronics Letters > 1989 > 25 > 8 > 516 - 517
Electronics Letters > 1989 > 25 > 23 > 1563 - 1565
Electronics Letters > 1990 > 26 > 17 > 1375 - 1377
Electronics Letters > 1991 > 27 > 10 > 865 - 866
Electronics Letters > 1992 > 28 > 10 > 935 - 937