@article{oai:tsukuba.repo.nii.ac.jp:00017245,
 author = {Koike, Naoyuki},
 issue = {2},
 journal = {Tsukuba Journal of Mathematics},
 month = {Oct},
 pages = {407--425},
 title = {Generalized helical immersions},
 volume = {22},
 year = {1998}
}