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Boice JD, Greene MH, Killen JY, Ellenberg SS, Keehn RJ, McFadden E, et al. (November 1983). "Leukemia and preleukemia after adjuvant treatment of gastrointestinal cancer with semustine (methyl-CCNU)". The New England Journal of Medicine. 309 (18): 1079–1084. doi:10.1056/NEJM198311033091802. PMID6353233.