@article{DAN_1981_258_5_a15,
     author = {V. F. Lazutkin},
     title = {Diffraction losses in open resonators. {A} geometric approach},
     journal = {Doklady Akademii Nauk},
     pages = {1089--1092},
     publisher = {mathdoc},
     volume = {258},
     number = {5},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_258_5_a15/}
}