@article {tan2007fine,
	title = {Fine particle counting with aerodynamic particle focusing and corona charging},
	journal = {Atmospheric Environment},
	volume = {41},
	number = {25},
	year = {2007},
	pages = {5271{\textendash}5279},
	publisher = {Pergamon},
	author = {Tan, ZC and Wexler, AS}
}