Heslop, P., Blair, P.S., Fleming, P., Hoghton, M., Marriott, A., & Russ, L. (2013). The Confidential Inquiry into premature deaths of people with intellectual disabilities in the UK: a population-based study. Lancet. 383 (9920), 889-895. 

Lauer, E., & McCallon, P. (2015). Mortality of People with Intellectual and Developmental Disabilities from Select US State Disability Service Systems and Medical Claims Data. Journal of Applied Research in Intellectual Disabilities, 28, 394-405