The Arithmetic of Elliptic Curves
《The Arithmetic of Elliptic Curves》 · 第 442 页 · Appendix C，Section 13「Modular Curves」，定义段
For a given elliptic curve $E/\mathbb Q$, if there exists a finite map $\phi:X_0(N)\to E$ defined over $\mathbb Q$ for some modular curve $X_0(N)$, then we say that the elliptic curve is modular and we call $\phi$ a modular parametrization.