Systems & Control Letters
Systems & Control Letters > 1995 > 25 > 1 > 1-7
Systems & Control Letters > 1996 > 27 > 5 > 267-274
Systems & Control Letters > 1996 > 28 > 3 > 159-165
Systems & Control Letters > 1997 > 30 > 4 > 159-164
Systems & Control Letters > 1997 > 31 > 2 > 103-113