@misc{klapper_ecotechnologies_for_1989, author={Klapper, H.}, title={Ecotechnologies for improving water quality}, year={1989}, howpublished = {conference lecture: Prague (CZ); 1989}, note = {Online available at: \url{} (DOI). Klapper, H.: Ecotechnologies for improving water quality. World Fed. of Engineering Organizations: Technical Congress '89. Prague (CZ), 1989.}}