1. Asahi K (2014) Ontake eruption viewed at close range. Kagaku 84:1226–1227 (in Japanese)
2. Cabinet Office (2015) Handbook for improving the volcanic shelter.
http://www.bousai.go.jp/kazan/shiryo/pdf/201512_hinan_tebiki4.pdf
. Accepted Dec 2015 (in Japanese)
3. Cas RAF, Wright JV (1987) Volcanic successions: modern and ancient. Chapman & Hall, London
4. Japan Metrological Agency (2014) Ontakesan (September 2014 Issue). Monthly commentary documents on volcanic activity.
http://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/monthly_v-act_doc/tokyo/14m09/312_14m09.pdf
. Accepted Oct 2014 (in Japanese)
5. Kaito F (2014) Eyewitness testimony 3. In: Yamatokeikokusha (ed) Document of the Ontake eruption. Yama-Kei Publishers, Tokyo (in Japanese)