@techreport{iiasa4989,
           month = {April},
            type = {IIASA Working Paper},
           title = {The Historical Development of Planning Law in North-Rhine Westphalia with Relevance to Environmental Protection},
         address = {IIASA, Laxenburg, Austria},
       publisher = {WP-96-037},
            year = {1996},
             url = {https://pure.iiasa.ac.at/id/eprint/4989/},
          author = {Gornig, M.}
}