EntityQ8073569· pop 5· linked from 8 articlesZoll surfaceSign in to saveSurface homeomorphic to a sphereConnectionsDavid HilbertEntitytopologyEntitysphereEntitydigital object identifierEntitysurfaceEntitydifferential geometryEntityQ118398EntityhomeomorphismEntitygeodesic curveEntityRiemannian manifoldEntityMathematische AnnalenEntityRadon transformEntityVictor GuilleminEntityPaul FunkEntityclosed geodesicEntityAdvances in MathematicsEntityJournal of Differential GeometryEntityArthur BesseEntityClaude LeBrunEntityCategoriesDifferential geometrySurfaces