@article{VTAMU_2019_24_126_a7,
     author = {A. Khellaf and S. Benarab and H. Guebbai and W. Merchela},
     title = {A class of strongly stable approximation for unbounded operators},
     journal = {Vestnik rossijskih universitetov. Matematika},
     pages = {218--234},
     year = {2019},
     volume = {24},
     number = {126},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VTAMU_2019_24_126_a7/}
}