Calculation of HELAS amplitudes for QCD processes using graphics processing unit (GPU)K. Hagiwara, J. Kanzaki, N. Okamura, D. Rainwater and T. StelzerEur. Phys. J. C, 70 1-2 (2010) 513-524DOI: https://doi.org/10.1140/epjc/s10052-010-1465-5