TY  - BOOK
AU  - Alchourron Carlos E
AU  -  Bulygin Eugenio
TI  - Normative systems
T2  - Library of Exact Philosophy. Ed by Mario Eunge. 5
SN  - 3211810196
U1  - R:(Z,91), L1 
PY  - 1971///
CY  - New York
PB  - Springer Verlag U. S. A.     
KW  - Philosophy-Critism
N1  - Bibliography: P 197-201
ER  -