@incollection{GrotehusmannKhelilSiekeretal.1993,
  author    = {Grotehusmann, D. and Khelil, A. and Sieker, F. and Uhl, M.},
  title     = {Alternative urban drainage concept and design},
  series = {Proceedings of the 6th International Conference on Urban Storm Drainage, Niagara Falls, Canada},
  booktitle = {Proceedings of the 6th International Conference on Urban Storm Drainage, Niagara Falls, Canada},
  pages     = {1213 -- 1218},
  year      = {1993},
  language  = {en}
}
@article{GrotehusmannKhelilSiekeretal.1994,
  author    = {Grotehusmann, D. and Khelil, A. and Sieker, F. and Uhl, M.},
  title     = {Alternative urban drainage concept and design},
  series = {Water Science and Technology},
  volume    = {29},
  journal   = {Water Science and Technology},
  number    = {1-2},
  pages     = {277 -- 282},
  year      = {1994},
  language  = {en}
}