@article{BaerBecker2014,
  author    = {Christian B{\"a}r and Christian Becker},
  title     = {Differential characters and geometric chains},
  journal   = {Lecture notes in mathematics : a collection of informal reports and seminars},
  volume    = {2112},
  pages     = {1 -- 90},
  doi       = {10.1007/978-3-319-07034-6_1},
  year      = {2014},
}