1. Department of Economic and Social Affairs, Population Divisionhttps://population.un.org/wpp/
2. Statistics Explainedhttp://ec.europa.eu/eurostat/statistics-explained/index.php/Population_structure_and_ageing
3. Eurostat Regional Yearbook,2019
4. Generalitat de Catalunyahttps://www.idescat.cat/indicadors/?id=anuals&n=10003
5. World Report on Ageing and Healthhttp://www.who.int/ageing/publications/world-report-2015/en/