@Article{acpd-6-6401-2006,
AUTHOR = {Laakso, L. and Gagn\'e, S. and Pet\"aj\"a, T. and Hirsikko, A. and Aalto, P. P. and Kulmala, M. and Kerminen, V.-M.},
TITLE = {Detecting charging state of ultra-fine particles: instrumental development and ambient measurements},
JOURNAL = {Atmospheric Chemistry and Physics Discussions},
VOLUME = {6},
YEAR = {2006},
NUMBER = {4},
PAGES = {6401--6429},
URL = {http://www.atmos-chem-phys-discuss.net/6/6401/2006/},
DOI = {10.5194/acpd-6-6401-2006}
}