@article{10_1017_S0017089501030075,
     author = {Berkani, M. and Sarih, M.},
     title = {On semi {B-Fredholm} operators},
     journal = {Glasgow mathematical journal},
     pages = {457--465},
     year = {2001},
     volume = {43},
     number = {3},
     doi = {10.1017/S0017089501030075},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089501030075/}
}