@article{oai:tsukuba.repo.nii.ac.jp:00016231,
 author = {Cerin, Zvonko},
 issue = {2},
 journal = {Tsukuba Journal of Mathematics},
 month = {Dec},
 pages = {177--202},
 title = {On various relative proper homotopy groups},
 volume = {4},
 year = {1980}
}