TY  - BOOK
AU  - Bell David J
AU  -  Jacobson David H
TI  - Singular optimal control problems
T2  - Mathematics in science and engineering: A series of monographs and textbook; 117
U1  - B2893, L5 
PY  - 1975///
CY  - London
PB  - Academic press        
KW  - Operational research
ER  -