🌐EnglishEnglishDeutschFrançaisItalianoNederlandsPolskiPortuguêsSvenskaTiếng ViệtTürkçeРусский한국어中文日本語EntityQ1307800· pop 19· linked from 208 articlesunit sphereset of points in 3D space of distance 1 from a fixed central pointAvailable in 19 languagesFrançaisDeutsch中文日本語ItalianoCzechEsperantoFinnishGreekNederlandsNorwegianConnectionsSpringer Science+Business MediaEntitymathematicsEntityCategories1 (number)Functional analysisSpheres