@book{VanLeeuwenChengReich2015,
  author    = {Peter Jan Van Leeuwen and Yuan Cheng and Sebastian Reich},
  title     = {Nonlinear data assimilation},
  isbn      = {978-3-319-18346-6},
  doi       = {10.1007/978-3-319-18347-3},
  year      = {2015},
}