Innami, Nobuhiro, Yoe Itokawa, Tetsuya Nagano, and Katsuhiro Shiohama. “Geodesic Families Characterizing Flat Metrics on a Cylinder and a Plane”. MATHEMATICA SCANDINAVICA 128, no. 2 (June 11, 2022). Accessed December 6, 2022. https://www.mscand.dk/article/view/132247.