@Article{acp-8-813-2008,
AUTHOR = {Kr\"uger, K. and Tegtmeier, S. and Rex, M.},
TITLE = {Long-term climatology of air mass transport through the Tropical  Tropopause Layer (TTL) during NH winter},
JOURNAL = {Atmospheric Chemistry and Physics},
VOLUME = {8},
YEAR = {2008},
NUMBER = {4},
PAGES = {813--823},
URL = {http://www.atmos-chem-phys.net/8/813/2008/},
DOI = {10.5194/acp-8-813-2008}
}