@article{ZNSL_1981_104_a14,
     author = {A. I. Lanin and M. M. Popov},
     title = {Behaviour of the whispering gallery rays in a~vicinity of a~point where curvature of the boundary vanishes},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {146--155},
     publisher = {mathdoc},
     volume = {104},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1981_104_a14/}
}