1. Kluge, F., Zagheni, E., Loichinger, E., and Vogt, T., The Advantages of Demographic Change after the Wave: Fewer and Older, but Healthier, Greener, and More Productive? PLoS ONE 9(9):e108501, 2014. doi: 10.1371/journal.pone.0108501 .
2. United Nations (2013) World Population Aging 2013. Department of Economic and Social Affairs. Population Division. http://www.un.org/en/development/desa/population/publications/pdf/ageing/WorldPopulationAgeingReport2013.pdf . Accessed 17 October 2014.
3. OECD (2014) “Doctors”, in OECD Factbook 2014: Economic, Environmental and Social Statistics. OECD Publishing. doi: 10.1787/factbook-2014-103-en
4. Ishikawa, T., Ohba, H., Yokooka, Y., Nakamura, K., and Ogasawara, K., Forecasting the absolute and relative shortage of physicians in Japan using a system dynamics model approach. Hum. Resour. Health, 2013. doi: 10.1186/1478-4491-11-41 .
5. Nomura, K., Physician Shortage in Japan: The New Postgraduate Medical Education Program and Physicians as a Human Medical Resource. Nippon Eiseigaku Zasshi. 66(1):22–28, 2011.