00293nam a2200109Ia 4500082001900000100003500019245005000054260002900104300001500133500000500148700003000153  a511.3bC678.IL  aCohen, M. R. and Nagel, Ernest  aIntroduction to logic and scientific methodb  aNew YorkbHarcourtc1934  axii, 467p.  a  aNagel, Ernest ; jt. auth.