@article{10_4064_sm_90_3_175_190,
     author = {M. Schechter and Robert Whitley},
     title = {Best {Fredholm} perturbation theorems},
     journal = {Studia Mathematica},
     pages = {175--190},
     publisher = {mathdoc},
     volume = {90},
     number = {3},
     year = {1988},
     doi = {10.4064/sm-90-3-175-190},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-90-3-175-190/}
}