1. Hiraki, K.: Trends in metal resource development and strategies for resource security, surface science for resource issues 114–115 (2014)
2. Kato, Y.: Taiheiyou no Reaasudei ga Nihon wo sukuu, Tokyo, PHP interface press, 167–180 (in Japanese) (2012)
3. Ministry of the Environment: Report of Technology Assessment of Environmental Impact, 223–228 (2011)
4. Tagami, T., Sakiyama, T., Funatsu, T., Hamanaka, A., Sasaoka, T., Shimada, H., Takahashi, T.: Study on deformation behavior of rare-earth elements-rich mud and applicability of sealing materials in seabed mining. In: Proceedings International Symposium on Earth Science and Technology, 161–164 (2017)