@article{ZNSL_1969_15_a8,
     author = {T. M. Popova},
     title = {The higher approximations for the eigen oscillations of the flat multimirrors resonator},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {142--153},
     publisher = {mathdoc},
     volume = {15},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1969_15_a8/}
}