@article{10_4064_cm_15_1_129_133,
     author = {W. Waliszewski},
     title = {On the tagency of sets in a metric space},
     journal = {Colloquium Mathematicum},
     pages = {129--133},
     publisher = {mathdoc},
     volume = {15},
     number = {1},
     year = {1966},
     doi = {10.4064/cm-15-1-129-133},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-15-1-129-133/}
}