1. Economic and social implications of aging societies;S Harper;Science,2014
2. Office for National Statistics. Living longer—how our population is changing and why it matters [Internet]. 2018 [cited 2018 Jun 11]. Available from: https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/ageing/articles/livinglongerhowourpopulationischangingandwhyitmatters/2018-08-13
3. New Frontiers in the Future of Aging: From Successful Aging of the Young Old to the Dilemmas of the Fourth Age;PB Baltes;Gerontology,2003
4. Institute of Medicine (US) Committee on Lesbian, Gay, Bisexual, and Transgender Health Issues and Research Gaps and Opportunities. The Health of Lesbian, Gay, Bisexual, and Transgender People: Building a Foundation for Better Understanding [Internet]. Washington (DC): National Academies Press (US); 2011 [cited 2018 Nov 5]. (The National Academies Collection: Reports funded by National Institutes of Health). Available from: http://www.ncbi.nlm.nih.gov/books/NBK64806/
5. British Medical Association. Growing older in the UK [Internet]. 2016 [cited 2018 Oct 24]. Available from: https://www.bma.org.uk/collective-voice/policy-and-research/public-and-population-health/healthy-ageing