@article{MZM_2017_102_3_a6,
     author = {Yu. P. Petrova},
     title = {Spectral {Asymptotics} for {Problems} with {Integral} {Constraints}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {405--414},
     publisher = {mathdoc},
     volume = {102},
     number = {3},
     year = {2017},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2017_102_3_a6/}
}