@Article{acpd-8-569-2008, AUTHOR = {Xie, S. and Liu, Z. and Chen, T. and Hua, L.}, TITLE = {Spatiotemporal variations of ambient PM$_{10}$ source contributions in Beijing in 2004 using positive matrix factorization}, JOURNAL = {Atmospheric Chemistry and Physics Discussions}, VOLUME = {8}, YEAR = {2008}, NUMBER = {1}, PAGES = {569--599}, URL = {http://www.atmos-chem-phys-discuss.net/8/569/2008/}, ISSN = {1680-7367} }