00293nam a2200121Ia 4500082002100000100002100021245003400042260003600076300003200112490001700144500000500161700000500166  a515.72bAu926.PS  aAupetit, Bernard  aA primer on spectral theoryb  aNew YorkbSpringer-Verlagc1991  axii, 193p. Index, Appendix.  aUniversitext  a  a