@article{HeuermannSchiek1995,
  author    = {Heuermann, Holger and Schiek, Burkhard},
  title     = {The double-LNN Calibration technique for scattering parameter measurements of microstrip devices},
  series = {Conference proceedings},
  journal   = {Conference proceedings},
  publisher = {NEXUS House},
  address   = {Kent},
  pages     = {343 -- 347},
  year      = {1995},
  language  = {en}
}
@article{HeuermannSchiek1992,
  author    = {Heuermann, Holger and Schiek, Burkhard},
  title     = {The In-Fixture Calibration Procedure Line-Network-Network-LNN},
  series = {Conference proceedings : monday 6th to thursday 9th september 1993, Palacio de Congresos, Madrid, Spain ; [the international conference and exhibition designed for the Microwave Community]},
  journal   = {Conference proceedings : monday 6th to thursday 9th september 1993, Palacio de Congresos, Madrid, Spain ; [the international conference and exhibition designed for the Microwave Community]},
  publisher = {Reed Exhibition Companies},
  address   = {Tunbridge Wells},
  isbn      = {0-946821-23-2},
  pages     = {500 -- 505},
  year      = {1992},
  language  = {en}
}