EntityQ11059889· pop 6· linked from 35 articlesHilbert's eighteenth problemSign in to saveOn lattices and sphere packing in Euclidean spaceConnectionsHilbert's problemsEntityJohannes KeplerEntityInternational Standard Book NumberEntityDavid HilbertEntitydigital object identifierEntityInternational Standard Serial NumberEntitythree-dimensional spaceEntitypolyhedronEntityEuclidean spaceEntityQ118398EntityCambridge University PressEntitycontinuum hypothesisEntitycubic crystal systemEntityQ22908627Entityaffine transformationEntityAmerican Mathematical SocietyEntitycyclic groupEntityword playEntitygroup actionEntitysymmetry groupEntityCategoriesGeometry problemsHilbert's problemsTessellation