@article{AUCMP_1998__39_1-2_a6,
     author = {Cs\"ornyei, Marrianna},
     title = {Differentiability points of a distance function},
     journal = {Acta Universitatis Carolinae. Mathematica et Physica},
     pages = {105--110},
     publisher = {mathdoc},
     volume = {39},
     number = {1-2},
     year = {1998},
     mrnumber = {1696608},
     zbl = {1045.26003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUCMP_1998__39_1-2_a6/}
}