@article{10_2298_FIL2107141A,
     author = {Boulbeba Abdelmoumen and Sadok Chakroun and Mnif Maher},
     title = {Perturbation results in the {Fredholm} theory and m-essential spectra of some matrix operators},
     journal = {Filomat},
     pages = {2141 },
     year = {2021},
     volume = {35},
     number = {7},
     doi = {10.2298/FIL2107141A},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.2298/FIL2107141A/}
}