"Geometría moderna." . . "Nichteuklidische Geometrie." . . "MATHEMATICS Geometry General." . . "Geometría no euclidiana." . . "Geometria no euclidiana" . . . "Geometry, Non-Euclidian" . . "Geometry, Non-Euclidian." . . "Lehrbuch" . . . . . . . . . . . . "Electronic books"@en . . . . "In the 1880s, over fifty years after the discovery of the hyperbolic plane, Poincare pointed out that this plane provides a very useful context for describing the properties of the solutions of an important class of differential equations." . . . . . . . . "The Poincaré half-plane a gateway to modern geometry"@en . . . . . . . "The Poincaré half-plane : a gateway to modern geometry" . "Géométrie hyperbolique." . . "Poincaré-Halbebene." . . "Geometrija Evklidska in hiperbolična geometrija." . . "Géométrie non-euclidienne." . . "Geometria non euclidea." . . "Meetkunde." . .