1. [1] Brunault, François Graphes d’isogénies entre courbes elliptiques (http://perso.ens-lyon.fr/francois.brunault/parigp)
2. [2] Cremona, John Elliptic curve data, 2017 (Optimality and the Manin constant, http://johncremona.github.io/ecdata)
3. [3] Edixhoven, Bass On the Manin constants of modular elliptic curves, Arithmetic algebraic geometry (Texel, 1989) (Progress in Mathematics) Tome 89, Birkhäuser, 1989, pp. 25-39
4. [4] Manin, Yuri I. Parabolic points and zeta-functions of modular curves, Math. USSR, Izv., Tome 6 (1972) no. 1, pp. 19-64
5. [5] Mazur, Barry Courbes elliptiques et symboles modulaires, Séminaire Bourbaki (1971/72) (Lecture Notes in Mathematics) Tome 317, Springer, 1973, pp. 277-294 (Exposé 414)