00319nam a2200121Ia 4500082002200000100002000022245005800042260003300100300001500133490003900148500000500187700000500192  a658.568bSh554.EC  aShewhart, W. A.  aEconomic control of quality of manufactured productb  aNew YorkbVan Nostrandc1931  axiv, 501p.  aBell telephone laboratories series  a  a