@article{10_14708_cm_v16i1_5738,
     author = {A. Ch\k{a}dzy\'nska},
     title = {On some classes of sets related to the symmetry of the tangency relation in a metric space},
     journal = {Commentationes Mathematicae},
     pages = { 219--228},
     publisher = {mathdoc},
     volume = {16},
     number = {1},
     year = {1972},
     doi = {10.14708/cm.v16i1.5738},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v16i1.5738/}
}