Effective-Lagrangian approach to γγ → WW I: Couplings and amplitudes O. Nachtmann, F. Nagel, M. Pospischil and A. Utermann Eur. Phys. J. C, 45 3 (2006) 679-691 Published online: 24 January 2006 DOI: 10.1140/epjc/s2005-02450-3