@article{RM_2018_73_2_a5,
     author = {A. R. Alimov and E. V. Shchepin},
     title = {Convexity of {Chebyshev} sets with~respect to tangent directions},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {366--368},
     publisher = {mathdoc},
     volume = {73},
     number = {2},
     year = {2018},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_2018_73_2_a5/}
}