TY  - BOOK
AU  - Johnson Ellis L
TI  - Integer programming :Facets subadditivity and duality for group and semi group problems
T2  - CBMS-NSF regional conference series in applied mathematics; 32
U1  - B2893,P3, M0 
PY  - 1980///
CY  - Philadeiphia
PB  - Philadelphia society for Industrial and Applied Mathematics   
ER  -