@article{oai:niigata-u.repo.nii.ac.jp:00002546, author = {Innami, Nobuhiro and Kim, Byung Hak}, issue = {6}, journal = {Proceedings of the Japan Academy, Ser. A Mathematical Sciences}, month = {}, note = {We prove that the Steiner ratio for hyperbokic surfaces is 1/2.}, pages = {77--79}, title = {Steiner ratio for hyperbolic surfaces}, volume = {82}, year = {2006} }