Kawamura Kazuhiro and Koshimizu Hironao and Miura Takeshi: Norms on C1 ([0, 1]) and their isometries. In: Acta scientiarum mathematicarum, (84) 1-2. pp. 239-261. (2018)
Koshimizu Hironao: Linear isometries on spaces consisting of absolutely continuous functions. In: Acta scientiarum mathematicarum, (80) 3-4. pp. 581-591. (2014)