1. Gleick PH (2000) The world’s water 2000–2001: the biennial report on freshwater resources. Island Press
2. Ercin AE, Hoekstra AY (2014) Water footprint scenarios for 2050: a global analysis. Environ Int 64:71–82
3. WWAP (UNESCO World Water Assessment Programme) (2019) The United Nations World Water Development Report 2019: leaving no one behind
4. UN (2018) Sustainable Development Goal 6: synthesis report 2018 on water and sanitation. New York, United Nation. www.unwater.org/app/uploads/2018/07/SDG6_SR2018_web_v5.pdf. (Accessed 14 Jan 2020)
5. Mekonnen MM, Hoekstra AY (2016) Four billion people facing severe water scarcity. Sci Adv 2(2):e1500323