1. Environmental Radioactivity and Radiation in Japan. http://www.kankyo-hoshano.go.jp/en/index.html . Accessed 19 Oct 2013
2. Fukushima Radiation Monitoring, Water, Soil and Entrainment. http://fmwse.suiri.tsukuba.ac.jp/FMWSE-english/indexEN.html . Accessed 19 Oct 2013
3. Fukushima Radiation Monitoring, Water, Soil and Entrainment, Japan Proficiency Test. http://fmwse.suiri.tsukuba.ac.jp/FMWSE-english/JapanPTEN.html . Accessed 19 Oct 2013
4. International Atomic Energy Agency (IAEA), Fukushima Nuclear Accident. http://www.iaea.org/newscenter/focus/fukushima/ . Accessed 19 Oct 2013
5. International Atomic Energy Agency (IAEA), Interlaboratory Comparisons and Proficiency Test. http://nucleus.iaea.org/rpst/ReferenceProducts/Proficiency_Tests/index.htm . Accessed 19 Oct 2013