1. United Nations, Department of Economic and Social Affairs, Population Division. World Population Prospects 2019: Highlights (ST/ESA/SER.A/423). 2019.
2. United Nations, Department of Economic and Social Affairs, Population Division. World population ageing 2015 (ST/ESA/SER.A/390). 2015.
3. Cresswell-Smith J, Amaddeo F, Donisi V, Forsman AK, Kalseth J, Martin-Maria N, Miret M, Walhbeck K. Determinants of multidimensional mental wellbeing in the oldest old: a rapid review. Soc Psychiatry Psychiatr Epidemiol. 2019;54:135–44.
4. World Health Organization. World report on ageing and health. 2015.
5. United Nations. The Sustainable Developmental Goals Report. 2018.