de Groot, J. Topological characterization of all subsets of the real number system. (English) Zbl 0029.23203 Proc. Akad. Wet. Amsterdam 50, 876-884 (1947). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 1 Document Keywords:Topology PDFBibTeX XMLCite \textit{J. de Groot}, Proc. Akad. Wet. Amsterdam 50, 876--884 (1947; Zbl 0029.23203)