@book{Laack2000,
  author    = {Laack, Walter van},
  title     = {Key to Eternity / Walter van Laack. [Transl. by Anneliese Wolstenholme]},
  publisher = {van Laack},
  address   = {Aachen},
  isbn      = {978-3-8311-0344-7},
  pages     = {256 S.},
  year      = {2000},
  language  = {en}
}
@book{Laack2022,
  author    = {Laack, Walter van},
  title     = {Greater Than the Entire Universe},
  publisher = {van Laack GmbH},
  address   = {Aachen},
  isbn      = {978-3-936624-52-6},
  pages     = {120 Seiten},
  year      = {2022},
  language  = {en}
}