@article{oai:tsukuba.repo.nii.ac.jp:00029699,
 author = {Kuwabara, Kenji},
 issue = {1},
 journal = {Tsukuba Journal of Mathematics},
 month = {Jun},
 pages = {49--59},
 title = {Grassmann geometry on the groups of rigid motions on the Euclidean and the Minkowski planes},
 volume = {30},
 year = {2006}
}