Needleman, HL; Schell, A; Bellinger, D; Leviton, A; Allred, EN. The long-term effects of exposure to low doses of lead in childhood. An 11-year follow-up report.. The New England Journal of Medicine. 1990, 322 (2): 83–8. PMID 2294437. doi:10.1056/NEJM199001113220203.
Needleman, HL; Schell, A; Bellinger, D; Leviton, A; Allred, EN. The long-term effects of exposure to low doses of lead in childhood. An 11-year follow-up report.. The New England Journal of Medicine. 1990, 322 (2): 83–8. PMID 2294437. doi:10.1056/NEJM199001113220203.