IEEE Transactions on Systems, Man, and Cybernetics, Volume 21

Volume 21, Number 1, January / February 1991

Volume 21, Number 2, March / April 1991

Volume 21, Number 3, May / June 1991

Volume 21, Number 4, July / August 1991

Volume 21, Number 5, September / October 1991

Volume 21, Number 6, November / December 1991