1. 1) World Health Organization, “WHO guidelines for indoor air quality: selected pollutants,” WHO, Geneva, 2010.
2. 2) Committee on Sick House Syndrome: Indoor Air Pollution, Ministry of Health, Labour and Welfare: 〈http://www.mhlw.go.jp/stf/shingi/2r9852000000ax9a.html#shingi128714〉, cited 7 September, 2015.