@article{MZM_2020_108_1_a4,
     author = {V. S. Klimov},
     title = {Variational {Inequalities} and {Analogs} of the {Hopf} {Theorems}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {64--80},
     publisher = {mathdoc},
     volume = {108},
     number = {1},
     year = {2020},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2020_108_1_a4/}
}