@article{10_4153_CJM_2012_022_4,
     author = {Sauer, N.W.},
     title = {Distance {Sets} of {Urysohn} {Metric} {Spaces}},
     journal = {Canadian journal of mathematics},
     pages = {222--240},
     year = {2013},
     volume = {65},
     number = {1},
     doi = {10.4153/CJM-2012-022-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-2012-022-4/}
}