Gavett SH, Haykal-Coates N, Highfill JW, Ledbetter AD, Chen LC, Cohen MD, Harkema JR, Wagner JG, Costa DL. World Trade Center fine particulate matter causes respiratory tract hyperresponsiveness in mice. Environ Health Perspect. 2003 Jun;111(7):981–91. PMID: 12782502; PMCID: PMC1241535.