Radiative return at - and B-factories: FSR for muon pair production at next-to-leading order H. Czyż, A. Grzelińska, J. H. Kühn and G. Rodrigo Eur. Phys. J. C, 39 4 (2005) 411-420 Published online: 15 February 2005 DOI: 10.1140/epjc/s2004-02103-1