@unpublished{LAENG18_in_prep,
   author = "A. Laeng and T. von Clarmann and G. Stiller and V. Sofieva and
             N. Kramarova and K. A. Walker and J. Zawodny and J. Plieninger",
   title  = "Creating longterm climate data records using transfer functions:
             methodology and application to {SAGE II, MIPAS} and {OMPS}
             ozone profile datasets",
   year   = "2018",           
   note   = "in preparation" }