TY  - BOOK
AU  - Pshenichnyi B N
TI  - Necessary conditions for an extremum
T2  - Pure and applied mathematics: a series of monographs
U1  - B43, L1 
PY  - 1971///
CY  - New York    
PB  -  Marcel Dekker       
N1  - Bibliography 223-225p
ER  -