@Article{acp-9-1711-2009,
AUTHOR = {Pathak, R. K. and Wu, W. S. and Wang, T.},
TITLE = {Summertime PM$_{2.5}$ ionic species in four major cities of  China: nitrate formation in an ammonia-deficient atmosphere},
JOURNAL = {Atmospheric Chemistry and Physics},
VOLUME = {9},
YEAR = {2009},
NUMBER = {5},
PAGES = {1711--1722},
URL = {http://www.atmos-chem-phys.net/9/1711/2009/},
DOI = {10.5194/acp-9-1711-2009}
}