000 00272nam a2200097Ia 4500
008 230915s9999 xx 000 0 und d
050 _aQA9 .P65 1954
100 _aG.POLYA
245 0 _aPATTERNS OF PLAUSIBLE INFERENCE: OF MATHMATICS AND PLAUSIBLE REASONING
942 _cBK
999 _c181974
_d181974