Collinear subtractions in hadroproduction of heavy quarks B. A. Kniehl, G. Kramer, I. Schienbein and H. Spiesberger Eur. Phys. J. C, 41 2 (2005) 199-212 Published online: 15 May 2005 DOI: 10.1140/epjc/s2005-02200-7