1. 1)ISO 20480-1:2017, Fine bubble technology - General principles for usage and measurement of fine bubbles - Part 1: Terminology.
2. 2)K-rip Fine bubble application case studies(4th ed.+ enlarged and supplemented edition). https://k-rip.gr.jp/publicca-tion/cat_publication/finebubble,(2022).
3. https://k-rip.gr.jp/wp/wp-content/uploads/2018/03/finebubble_ver4.pdf
4. 3)S. Nishitani, Y. Umeda, H. Honma, O. Takai, K. Tashiro ; Hyomen Gijutsu Lecture series, Vol.146, p.146(2022).
5. 4)H. Honma, H. Kosai, S. Sugimoto ; Published Granted Patent(Second Level)JP4242310B2(2004).