@Article{acp-9-6717-2009,
AUTHOR = {Kr\"uger, K. and Tegtmeier, S. and Rex, M.},
TITLE = {Variability of residence time in the Tropical Tropopause Layer during Northern Hemisphere winter},
JOURNAL = {Atmospheric Chemistry and Physics},
VOLUME = {9},
YEAR = {2009},
NUMBER = {18},
PAGES = {6717--6725},
URL = {http://www.atmos-chem-phys.net/9/6717/2009/},
DOI = {10.5194/acp-9-6717-2009}
}