↑ Lave, Lester B. (1973). "An Analysis of the Association Between U.S. Mortality and Air Pollution". J. Amer. Statistical Association. 68: 342. Unknown parameter |coauthors= ignored (|author= suggested) (help)
↑ Mokdad, Ali H. (2004). "Actual Causes of Death in the United States, 2000". J. Amer. Med. Assoc. 291 (10): 1238–45. doi:10.1001/jama.291.10.1238. PMID15010446. Unknown parameter |coauthors= ignored (|author= suggested) (help)
↑ Region 4: Laboratory and Field Operations — PM 2.5 (2008).PM 2.5 Objectives and History. U.S. Environmental Protection Agency.
