|   | 1 |  initial version  | 
The reference is here: http://www.sagemath.org/doc/reference/plane_curves/index.html.
Concerning torsion subgroups over number fields, there is a specific module documented here: http://www.sagemath.org/doc/reference/plane_curves/sage/schemes/elliptic_curves/ell_torsion.html
 Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.
 
                
                Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.