Theta functions, modular invariance, and strings por Luis Alvarez-Gaumé, Gregory Moore, e Cumrun Vafa - Comm. Math. Phys. Volume 106, Number 1 (1986) [[1]]
rutgers.edu
rci.rutgers.edu
Differential equations, duality and modular invariance por Yi-Zhi Huang - Department of Mathematics, Rutgers University [[2]]