00732nam0-22002651i-450-990001126810403321000112681FED01000112681(Aleph)000112681FED0100011268120000920d1971----km-y0itay50------baengNormative systemsby Alchourron and Bulyg in .Wien [etc.]Springer-Verlag1971Library of Exact Philosophy5Alchourrón,Carlos E.348350Bulygin,EugenioITUNINARICAUNIMARCBK99000112681040332110-M-3719046MA1MA1Normative systems345053UNINAING01