@article{Baer2015,
  author    = {Christian B{\"a}r},
  title     = {Green-Hyperbolic Operators on Globally Hyperbolic Spacetimes},
  journal   = {Communications in mathematical physics},
  volume    = {333},
  number    = {3},
  pages     = {1585 -- 1615},
  doi       = {10.1007/s00220-014-2097-7},
  year      = {2015},
}