@article{CLARMANN10_ACP_TREND,
   author = "T. von Clarmann and G. Stiller and U. Grabowski
             and E. Eckert and J. Orphal",
   title  = "Technical Note: {T}rend estimation from irregularly
             sampled, correlated data",
   journal= "Atmos. Chem. Phys.",
   volume = "10",
   pages  = "6737-6747",
   year   = "2010"   }