00475nam a2200157Ia 450000500170000000800460001703700120006304000200007504100130009508400190010810000180012724500590014526000500020430000130025449000500026720250508155001.0008  250505s9999    xx            000 0 eng d  aTextual  aFEDLbengcFEDL  aeng2eng  a500, HEMqFEDL  aHempel Carl G 0aFundamentals of concept formation in empirical science  aChicago, USAbThe University of Chicagoc1952  aiii,93p.  aInternational encyclopedia of unified science