@article{oai:tsukuba.repo.nii.ac.jp:00016156,
 author = {Shiga, Koichi},
 issue = {1},
 journal = {Tsukuba Journal of Mathematics},
 month = {Jun},
 pages = {41--50},
 title = {On a relation between the total curvature and the measure of rays},
 volume = {6},
 year = {1982}
}