1. World Population Prospects: The 2017 Revision, Key Findings and Advance Tables
https://reliefweb.int/sites/reliefweb.int/files/resources/WPP2017_KeyFindings.pdf
2. An introduction to the macroeconomics of aging
3. Ageing in the Twenty-First Century: A Celebration and a Challenge
https://www.unfpa.org/sites/default/files/pub-pdf/Ageing%20report.pdf
4. Ageing Report: Europe Needs to Prepare for Growing Older
http://ec.europa.eu/economy_finance/articles/structural_reforms/2012-05-15_ageing_report_en.htm
5. Long-Term Care for the Elderly. Provisions and Providers in 33 European Countries
https://doi.org/10.2838/87307