REFERENCES
- ALVARADO , F. L. , and MUKUNDON , R. , 1969 , Int. J. Control , 9 , 665 .
- AXELBAND , E. I. , 1965 , Preprints of the Joint Automatic Control Conference ( Renssalaer Polytechnic Institute , Troy , N.Y. ), p. 374 ; 1966, I.E.E.E. Trans, autom. Control, AC-11, 42 .
- BUTKOVSKII , A. G. , 1961a , Automatn remote Control , 22 , 17 ; 1961b, Ibid., 22, 1156; 1961 c, Ibid., 22, 1429; 1963, Ibid., 24, 1106; Ibid., 1964, 24, 1056 .
- BUTKOVSKII , A. G. ,LEKNER, A. YA , 1960 , Automatn remote Control , 21 , 472 .
- CHAUDHURI , A. K. , 1965 , Int. J. Control , 11 , 365 .
- DENN , M. M. , 1966 , Int. J. Control , 4 , 167 .
- GRAHAM , J. W. , and D'SOUZA , A. F. , 1969 , Preprints of the Joint Automatic Control Conference , Boulder , Col. , p. 703 .
- KHATRI , H. C. , and GOODSON , R. E. , 1966 , J. bas. Engng , 88 , 337 .
- KIM , M. , and ERZBERGER , H. , 1967 , I.E.E.E. Trans, autom. Control , 12 , 22 .
- McCAUSLAND , L. , 1963 , J. Electron. Control , 14 , 655 .
- PIERRE , D. A. , and HIGGINS , T. J. , 1963 , Preprint No. 30.4.63, Eighteenth Annual I.S.A. Conference .
- SAKAWA , Y. , 1966 , I.E.E.E. Trans, autom. Control , AC-11 , 35 .
- SCHULTZ , D. G. , and MELSA , J. L. , 1967 , State Functions and Linear Control Systeiw ( New York McGraw-Hill ), Chaps. 7 and 8 , p. 255 .
- WANG , P. K. C. , and TUNG , F. , 1963 , Reprints of Technical Papers of the Fourth Joint Automatic Control Conference ( Minneapolis , Minn. University of Minnesota ), p. 16 ; 1964, Trans. Am. Soc. mech. Engrs, 86, Series D, 67 .
- †Communicated by the Author.