@book{HaenselNeumannHudel1993,
  author    = {Horst H{\"a}nsel and Werner Neumann and Erich Hudel},
  title     = {Physik : Bd. 2 Elektrizit{\"a}t, Optik, Raum und Zeit},
  volume    = {2},
  isbn      = {3-86025-304-2},
  year      = {1993},
}