1) Ministry of Health, Labour and Welfare: <http://www.mhlw.go.jp/shingi/2007/08/dl/s0803-5g.pdf>, cited 9 August, 2010.
2) The Yuumi Memorial Foundation for Home Health Care: <http://www.zaitakuiryo-yuumizaidan.com/data/file/data1_20080819035400.pdf>, cited 9 August, 2010.