@article{10_21136_CPM_1969_117669,
     author = {Neubrunn, Tibor and \v{S}al\'at, Tibor},
     title = {Distance sets, ratio sets and certain transformations of sets of real numbers},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky},
     pages = {381--393},
     publisher = {mathdoc},
     volume = {094},
     number = {4},
     year = {1969},
     doi = {10.21136/CPM.1969.117669},
     mrnumber = {0257309},
     zbl = {0188.11501},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPM.1969.117669/}
}