00322nam a2200121Ia 4500082002100000100002100021245003900042260004300081300001300124490005300137500000500190700000500195  a519.541bW539.SM  aWetherill, G. B.  aSequential methods in statisticsb  aLondonbChapman & Hall/CRC Pressc1975  ax, 232p.  aMonographs on Applied Probability and Statistics  a  a