@article{KuenstlerXiaWeinholdetal.2000,
  author    = {Wolfgang K{\"u}nstler and Zhongfu Xia and Till Weinhold and Andreas Pucher and Reimund Gerhard},
  title     = {Piezoelectricity of porous polytetrafluoroethylene single- and multiple-film electrets containing high charge densities of both polarities},
  year      = {2000},
}