@article{EngelBoenischUllrichetal.2017,
  author    = {Andreas Engel and Harald B{\"o}nisch and Markus Ullrich and Robert Sitals and Olivier Membrive and Fran{\c{c}}ois Danis and Cyril Crevoisier},
  title     = {Mean age of stratospheric air derived from AirCore observations},
  journal   = {Atmospheric chemistry and physics. Discussions},
  number    = {104},
  pages     = {1 -- 36},
  doi       = {10.5194/acp-2017-104},
  year      = {2017},
}