On the origin of cyclotron lines in the spectra of X-ray pulsars A. A. Mushtukov, J. Poutanen, V. F. Suleimanov, S. S. Tsygankov, D. I. Nagirner, V. Doroshenko and A. A. Lutovinov EPJ Web of Conferences, 64 (2014) 02005 Published online: 08 January 2014 DOI: 10.1051/epjconf/20136402005