Hammer, Preston C. Kuratowski’s closure theorem. (English) Zbl 0137.15503 Nieuw Arch. Wiskd., III. Ser. 8, 74-80 (1960). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 5 Documents Keywords:topology PDF BibTeX XML Cite \textit{P. C. Hammer}, Nieuw Arch. Wiskd., III. Ser. 8, 74--80 (1960; Zbl 0137.15503) OpenURL