@article{DAN_1979_248_5_a16,
     author = {V. I. Alfyorov and A. S. Biriukov and L. M. Dmitriev and Yu. E. Markachev and V. M. Marchenko and A. M. Prokhorov},
     title = {On the possibility of obtaining the inversion of energy level populations in the heterogeneous
},
     journal = {Doklady Akademii Nauk},
     pages = {1093--1096},
     publisher = {mathdoc},
     volume = {248},
     number = {5},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1979_248_5_a16/}
}