@article{MZM_1991_49_5_a18,
     author = {V. I. Yudovich},
     title = {Cosymmetry, degeneration of solutions of operator equations, and onset of a filtration convection},
     journal = {Matemati\v{c}eskie zametki},
     pages = {142--148},
     year = {1991},
     volume = {49},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1991_49_5_a18/}
}