@article{DAN_1980_254_3_a8,
     author = {A. N. Tikhonov},
     title = {On normal solutions of approximate systems of linear algebraic equations},
     journal = {Doklady Akademii Nauk},
     pages = {549--554},
     publisher = {mathdoc},
     volume = {254},
     number = {3},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_254_3_a8/}
}