@article{GDZPPN002093863, title = {Rational Isogenies of Prime Degree.}, journal = {Inventiones mathematicae}, volume = {46}, year = {1978}, pages = {129-162}, zbl = {0386.14009}, url = {http://dml.mathdoc.fr/item/GDZPPN002093863} }
Mazur, B. Rational Isogenies of Prime Degree.. Inventiones mathematicae, Tome 46 (1978) pp. 129-162. http://gdmltest.u-ga.fr/item/GDZPPN002093863/