@article{TM_2019_305_a15,
     author = {Alexei V. Penskoi},
     title = {Isoperimetric {Inequalities} for {Higher} {Eigenvalues} of the {Laplace--Beltrami} {Operator} on {Surfaces}},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {291--308},
     publisher = {mathdoc},
     volume = {305},
     year = {2019},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_2019_305_a15/}
}