@techreport{kral17[TUW-261028], author = {Kral, Ulrich and Allesch, Astrid and Rechberger, Helmut}, title = {{D}er st{\"a}dtische {U}ntergrund als {R}ohstoffmine? ({P}rojekt suro)}, institution = {{E}226 - {I}nstitut f{\"u}r {W}asserg{\"u}te und {R}essourcenmanagement; {T}echnische {U}niversit{\"a}t {W}ien}, year = {2017}, number = {23}, url = {http://publik.tuwien.ac.at/files/publik_261028.pdf} }