Ellipse at the Encyclopedia of Mathematics -LRB- Springer -RRB- Ellipse at Planetmath Liens externes Apollonius 'Derivation of the Ellipse at Convergence Ellipse & Hyperbola Construction - An interactive sketch showing how to trace the curves of the ellipse and hyperbola.
Autres sites Web Ellipse & Hyperbola Construction - Un croquis interactif montrant comment tracer les courbes de l'ellipse et de l'hyperbola.