1. N. Aayog: Composite water management index—a tool for water management (2019)
2. W. H. Organisation: Fact sheet on “Drinking water, 14 June 2019. Available https://www.who.int/news-room/fact-sheets/detail/drinking-water
3. Hoekstra, A., Mekonnen, M.: Four billion people facing severe water scarcity, 12 February 2016. Available https://advances.sciencemag.org/content/advances/2/2/e1500323.full.pdf
4. The 11 cities most likely to run out of drinking water, British Broadcasting Cooperation, 11 February 2018. Available https://www.bbc.com/news/world-42982959
5. Aniket Kadam, S.B.: Water purifier Market by Technology (UV, RO, and Gravity based), Distribution Channel (Retail Sales, Direct Sales, and Online), Portability (Portable, and Non-portable), and End User (Commercial and Residential), June 2019. Available https://www.alliedmarketresearch.com/water-purifier-market