@article{Timpf1999,
  author    = {Sabine Timpf},
  title     = {Abstraction, levels of detail, and hierarchies in map series},
  journal   = {Lecture Notes in Computer Science},
  volume    = {1661},
  pages     = {125 -- 139},
  doi       = {10.1007/3-540-48384-5_9},
  year      = {1999},
}