@article{10_1017_S0017089513000189,
     author = {\'ALVAREZ, T.},
     title = {STRICTLY {SINGULAR} {PERTURBATION} {OF} {ALMOST} {SEMI-FREDHOLM} {LINEAR} {RELATIONS} {IN} {NORMED} {SPACES}},
     journal = {Glasgow mathematical journal},
     pages = {211--219},
     year = {2014},
     volume = {56},
     number = {1},
     doi = {10.1017/S0017089513000189},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089513000189/}
}