@article{Baltzer1980,
  author    = {Baltzer, Wolfgang},
  title     = {Betriebseinrichtung in Strassentunneln},
  series = {Strassenverkehrstechnik. 24 (1980), H. 4},
  journal   = {Strassenverkehrstechnik. 24 (1980), H. 4},
  isbn      = {0039-2219},
  pages     = {123 -- 129},
  year      = {1980},
  language  = {de}
}
@article{Alt1980,
  author    = {Alt, Helmut},
  title     = {Kurzschlußstromberechnung},
  series = {Elektrizit{\"a}tswirtschaft},
  volume    = {Jg. 79},
  journal   = {Elektrizit{\"a}tswirtschaft},
  number    = {H. 10},
  issn      = {0013-5496},
  pages     = {379 -- 382},
  year      = {1980},
  language  = {de}
}