1. European Commission , Closing the loop: Commission adopts ambitious new Circular Economy Package to boost competitiveness, create jobs and generate sustainable growth , 2015 , http://europa.eu/rapid/press-release_IP-15-6203_en.htm
2. The Finnish Innovation Fund Sitra, Leading the cycle – Finnish road map to a circular economy 2016–2025, 2017, https://www.sitra.fi/en/projects/leading-the-cycle-finnish-road-map-to-a-circular-economy-2016-2025/#what-is-it-about
3. European Commission , Closing the loop - An EU action plan for the Circular Economy , Brussels , 2015 , http://eur-lex.europa.eu/resource.html?uri=cellar:8a8ef5e8-99a0-11e5-b3b7-01aa75ed71a1.0012.02/DOC_1andformat=PDF
4. B. E. Rittmann , in Source Separation and Decentralization for Wastewater Management , ed. T. Larsen , K. Udert and J. Lienert , IWA , London , 2013
5. Determination of the Internal Chemical Energy of Wastewater