http://en.wikipedia.org/wiki/Image:Quadric_Hyperbolic_Paraboloid.jpg This image is ineligible for copyright and therefore is in the public domain, because...
DescriptionIperboloide-parabolico-generico.jpg English: Polyhedral approximation of a generic (asymmetric) hyperbolic paraboloid. Approssimazione poliedrica di un...
hyperbolic transformation of ellipse which can be the directrix of a quadric (ellipsoid, paraboloid, hyperboloid). https://www.researchgate.net/profile/Hasan-Isawi...
