00478nam a22001577a 450000500170000002000180001710000200003524500390005526000470009430000120014149000460015350000550019965000230025465000240027765000190030120260114161109.0  a9780521866293  aDavies, Brian E  aLinear operators and their spectra  aNew YorkbCambridge university pressc2007  axii+451  aCambridge studies in advanced mathematics  aCambridge studies in advanced mathematics Vol. 106  aFourier transforms  aPerturbation theory  aPseudospectrum