1. Council Directive 91/271/EEC of 21 May 1991 Concerning Urban Waste-Water Treatmenthttps://eur-lex.europa.eu/legal-content/EN/TXT/?uri=celex%3A31991L0271
2. Report Controlli su Impianti di Depurazione 2018https://www.arpa.sicilia.it/wp-content/uploads/2017/12/REPORT-CONTROLLI-SCARICHI-IDRICI-2018-dati-2017.pdf
3. Verso una Economia Circolarehttps://ec.europa.eu/commission/priorities/jobs-growth-and-investment/towards-circular-economy_it
4. 9th Technical Assessment on UWWTD Implementationhttp://ec.europa.eu/environment/water/water-urbanwaste/implementation/pdf/9th%20Technical%20assessment%20of%20information%20on%20the%20implementation%20of%20Council%20Directive%2091-271-EEC.pdf
5. Development of a web-based tool for the calculation of costs of different wastewater treatment and reuse scenarios