@article{DAN_1973_212_6_a1,
     author = {L. F. German and V. P. Soltan and P. S. Soltan},
     title = {Certain properties of $\mathrm{d}$-convex sets},
     journal = {Doklady Akademii Nauk},
     pages = {1276--1279},
     publisher = {mathdoc},
     volume = {212},
     number = {6},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_212_6_a1/}
}