00322nam a2200121Ia 4500082002200000100002700022245005300049260003400102300001500136490003900151500000500190700000500195  a519.233bSi587.BT  aSilverstein, Martin L.  aBoundary theory for symmetric markov processesb  aBerlinbSpringer-Verlagc1976  axvi, 313p.  aLecture notes in Mathematicsv 516  a  a