00320nam a2200121Ia 4500082002100000100003000021245002700051260003900078300001500117490005600132500000500188700000500193  a338.528bC875.CC  aCowles, Alfred and Others  aCommon-stock indexesb  aBloomingtonbPrincipia Pressc1939  axiv, 499p.  aCowels commission for research in Economics v no.3  a  a