Mafra, Carlos R. Quantum Gravity & Unified Theories, AEI-Golm, MPI for Gravitational Physics, Max Planck Society;
1003.0678 (Preprint), 298KB
JHEP2010_017.pdf (Any fulltext), 830KB
Gomez, H., & Mafra, C. R. (2010). The Overall Coefficient of the Two-loop Superstring Amplitude Using Pure Spinors. Journal of high energy physics: JHEP, 2010(05): 017. doi:10.1007/JHEP05(2010)017.