References
- MAHALANOBIS , A. K. , 1960 ,. J. Electron. Contr. , 8 , 307 ; 1961, Trans. Amer. Inst.elect. Engrs, 57, 277 .
- GOLDEN , W. H. , and WEAVER , C. H. , 1963 , Trans. Amer. Inst, elect. Engrs , 66 , 105 .
- HART , J. E. , 1955 , Trans. Amer. Inst, elect. Engrs , 74 , 83 .
- †Communicated by the Authors.