1. EPA. Energy efficiency for water and wastewater utilities. On-line: water.epa.gov/infrastructure/sustain/energyefficiency.cfm, Sept. 2013.
2. Eurostat. Consumption of energy. On-line: http://epp.eurostat.ec.europa.eu/statistics_explained/index.php/Consumption_of_energy, Aug. 2012.
3. E. Cabrera, M.A. Pardo, R. Cobacho, E. Cabrera Jr. , Energy audit for water networks, J. Water Res. Plann. Managm., 136 (2010) 669-677.
4. EU (European Union), 2005. Directive 2005/32/EC of the European parliament and of the council establishing a framework for the setting of ecodesign requirements for energy-using products, European Commission, Brussels.
5. N. Dizadji, P. Entezar, A. Shabani, Energy savings in pumps, World Academy of Science, Engineering and Technology, 2012, 909-912.