@article{IM2_2019_83_6_a4,
     author = {I. G. Tsar'kov},
     title = {Smooth solutions of the eikonal equation and the~behaviour of local minima of the distance function},
     journal = {Izvestiya. Mathematics },
     pages = {1234--1258},
     publisher = {mathdoc},
     volume = {83},
     number = {6},
     year = {2019},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2019_83_6_a4/}
}