00325nam a2200121Ia 4500008004100000020005500041040000800096082001600104100002100120245004000141260000900181264001300190231129s1983||||xx |||||||||||||| ||spa||  a84-253-0250-1                                       bspa  aR 510 N553s  aNewman  James R. 0aSigma : el mundo de las matematicas  c1983  aGrijalbo