Grzedzielski, S., Swaczyna, P., Czechowski, A., & Hilchenbach, M. (2014). Solar wind He pickup ions as source of tens-of-keV/n neutral He atoms observed by the HSTOF/SOHO detector. Astronomy and Astrophysics, 563: A134. doi:10.1051/0004-6361/201322927.