@article{Gruening2018,
  author    = {Gr{\"u}ning, Helmut},
  title     = {Wassersensible Zukunftsst{\"a}dte},
  series = {Transforming Cities},
  volume    = {2018},
  journal   = {Transforming Cities},
  number    = {2},
  pages     = {38 -- 43},
  year      = {2018},
  language  = {de}
}
@misc{Gruening2018,
  author    = {Gr{\"u}ning, Helmut},
  title     = {Warum regnet es so viel?},
  year      = {2018},
  language  = {de}
}