- Kohei Arai, editor, Intelligent Computing - Proceedings of the 2021 Computing Conference, Volume 2, SAI 2021, Virtual Event, 15-16 July, 2021. Volume 284 of Lecture Notes in Networks and Systems, Springer, 2021.
- Kohei Arai, editor, Intelligent Computing - Proceedings of the 2021 Computing Conference, Volume 3, SAI 2021, Virtual Event, 15-16 July, 2021. Volume 285 of Lecture Notes in Networks and Systems, Springer, 2021.