Literature

I've seen a version of Theorem 4.1 referred to in the following papers:

1. Ribet: Torsion points on $J_0(N)$ and Galois representations
2. Loïc Merel and William Stein: The field generated by the points of small prime order on an elliptic curve
3. Ken Ono and William McGraw: Modular form Congruences and Selmer groups (McGraw will speak about this next week in this seminar!)
4. Momose and Ozawa: Rational points of modular curves $X_{\split }(p)$