@Article{acpd-12-1517-2012,
AUTHOR = {Geibel, M. C. and Messerschmidt, J. and Gerbig, C. and Blumenstock, T. and Hase, F. and Kolle, O. and Lavri\v{c}, J. V. and Notholt, J. and Palm, M. and Rettinger, M. and Schmidt, M. and Sussmann, R. and Warneke, T. and Feist, D. G.},
TITLE = {Calibration of column-averaged CH$_{4}$ over European TCCON FTS sites with airborne in-situ measurements},
JOURNAL = {Atmospheric Chemistry and Physics Discussions},
VOLUME = {12},
YEAR = {2012},
NUMBER = {1},
PAGES = {1517--1551},
URL = {http://www.atmos-chem-phys-discuss.net/12/1517/2012/},
DOI = {10.5194/acpd-12-1517-2012}
}