1. Office of National Statistics, 2011 census data. http://www.ons.gov.uk/ons/guide-method/census/2011/census-data/2011-census-data-catalogue/index.html
2. GeoHive Population Statistics. http://www.geohive.com/earth/pop_gender.aspx
3. NICE Guidelines (NG23). Menopause: diagnosis and management. https://www.nice.org.uk/guidance/ng23
4. Duration of Menopausal Vasomotor Symptoms Over the Menopause Transition