Calculation of infrared-divergent Feynman diagrams with zero mass threshold J. Fleischer, V.A. Smirnov, A. Frink, J. Körner, D. Kreimer, K. Schilcher and J.B. Tausk Eur. Phys. J. C, 2 4 (1998) 747-756 Published online: 20 February 1998 DOI: 10.1007/s100529800721