@article{DAN_1970_191_5_a1,
     author = {A. A. Bershtein},
     title = {Necessary and sufficient conditions for the occurrence of points of the {Markov} spectrum in the {Lagrange} spectrum},
     journal = {Doklady Akademii Nauk},
     pages = {971--973},
     publisher = {mathdoc},
     volume = {191},
     number = {5},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1970_191_5_a1/}
}