@article{RoeckmannBrassBorchersetal.2011,
  author    = {Thomas R{\"o}ckmann and Marc Brass and Reinhard Borchers and Andreas Engel},
  title     = {The isotopic composition of methane in the stratosphere : high-altitude balloon sample measurements},
  journal   = {Atmospheric chemistry and physics / Discussions},
  volume    = {11},
  pages     = {12039 -- 12102},
  doi       = {doi:10.5194/acpd-11-12039-2011},
  year      = {2011},
}