@article{DE_1980_16_3_a20,
     author = {V. G. Boltyanskii and L. K. Nikolaev},
     title = {A computer experiment in calculation of light trajectories},
     journal = {Differencialʹnye uravneni\^a},
     pages = {548--550},
     publisher = {mathdoc},
     volume = {16},
     number = {3},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1980_16_3_a20/}
}