Askwith, E. H. (1917). A Course of Pure Geometry: The properties of the conic sections (Revised ed.). Cambridge University Press.
Cita Chicago (17th ed.)Askwith, Edward Harrison. A Course of Pure Geometry: The Properties of the Conic Sections. Revised ed. Cambridge: Cambridge University Press, 1917.
Cita MLA (9th ed.)Askwith, Edward Harrison. A Course of Pure Geometry: The Properties of the Conic Sections. Revised ed. Cambridge University Press, 1917.
Atenció: Aquestes cites poden no estar 100% correctes.