Theisen, Stefan Quantum Gravity & Unified Theories, AEI-Golm, MPI for Gravitational Physics, Max Planck Society;
PhLB233-1989.pdf (Publisher version), 414KB
Ferrara, S., Lüst, D., & Theisen, S. (1989). Target space modular invariance and low-energy couplings in orbifold compacifications. Physics Letters B, 233(1-2), 147-152. doi:10.1016/0370-2693(89)90631-X.