@article{10_4064_sm_53_1_15_27,
     author = {Clifford Kottman},
     title = {Subsets of the unit ball the are separated by more than one},
     journal = {Studia Mathematica},
     pages = {15--27},
     publisher = {mathdoc},
     volume = {53},
     number = {1},
     year = {1975},
     doi = {10.4064/sm-53-1-15-27},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-53-1-15-27/}
}