@article{oai:repository.dl.itc.u-tokyo.ac.jp:00040361,
 author = {Saeki, Akihiro},
 issue = {3},
 journal = {Journal of mathematical sciences, the University of Tokyo},
 month = {},
 note = {application/pdf},
 pages = {617--629},
 title = {Some foliations on ruled surfaces},
 volume = {1},
 year = {1994}
}