von Essen CF, Bagshaw MA, Bush SE, Smith AR, Kligerman MM (September 1987). "Long-term results of pion therapy at Los Alamos". International Journal of Radiation Oncology, Biology, Physics. 13 (9): 1389–98. doi:10.1016/0360-3016(87)90235-5. PMID3114189.
von Essen CF, Bagshaw MA, Bush SE, Smith AR, Kligerman MM (September 1987). "Long-term results of pion therapy at Los Alamos". International Journal of Radiation Oncology, Biology, Physics. 13 (9): 1389–98. doi:10.1016/0360-3016(87)90235-5. PMID3114189.