Chen, L.-W. A., J. G. Watson, J. C. Chow, D. W. DuBois, and L. Herschberger (2010), Chemical mass balance source apportionment for combined PM2.5 measurements from U.S. non-urban and urban long-term networks, Atmos. Environ., 44, 4908-4918.

Bahadur, R., Y. Feng, L. M. Russell, and V. Ramanathan (2011), Impact of California's air pollution laws on black carbon and their implications for direct radiative forcing, Atmos. Environ., 45, 1162-1167.