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@article{DAN_1977_232_4_a7, author = {V. Ya. Ivrii}, title = {The wave fronts of the solutions of the system that describes crystal optics}, journal = {Doklady Akademii Nauk}, pages = {763--765}, publisher = {mathdoc}, volume = {232}, number = {4}, year = {1977}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1977_232_4_a7/} }
V. Ya. Ivrii. The wave fronts of the solutions of the system that describes crystal optics. Doklady Akademii Nauk, Tome 232 (1977) no. 4, pp. 763-765. http://geodesic.mathdoc.fr/item/DAN_1977_232_4_a7/