@article{05021961,
title = {The distribution of group structures on elliptic curves over finite prime fields.},
journal = {Documenta Mathematica},
volume = {11},
year = {2006},
pages = {119-142},
zbl = {1130.11054},
language = {en},
url = {http://dml.mathdoc.fr/item/05021961}
}
Gekeler, Ernst-Ulrich. The distribution of group structures on elliptic curves over finite prime fields.. Documenta Mathematica, Tome 11 (2006) pp. 119-142. http://gdmltest.u-ga.fr/item/05021961/