NASA - National Aeronautics and Space Administration

Philip, S., R. Martin, A. van Donkelaar, J. W. Lo, Y. Wang, D. Chen, L. Zhang, P. Kasibhatla, S. Wang, Q. Zhang, Z. Lu, D. Streets, S. Bittman, and D. J. Macdonald (2014), Global Chemical Composition of Ambient Fine Particulate Matter for Exposure Assessment, Environ. Sci. Technol., 48, 13060-13068, doi:10.1021/es502965b.