@article{STILLER12_ACP_AGE,
   author = "G. P. Stiller and T. von Clarmann and F. Haenel and B. Funke and
             N. Glatthor and U. Grabowski and S. Kellmann and M. Kiefer and
             A. Linden and S. Lossow and M. L{\'o}pez-Puertas",
   title  = "Observed temporal evolution of global mean age of
             stratospheric air for the 2002 to 2010 period",
   journal= "Atmos. Chem. Phys.",
   volume = "12",
   pages  = "3311-3331",
   doi    = "10.5194/acp-12-3311-2012",
   year   = "2012"   }