@article{oai:soar-ir.repo.nii.ac.jp:00018397,
 author = {Futa, Yuichi and Okazaki, Hiroyuki and Shidama, Yasunari},
 issue = {1},
 journal = {Formalized Mathematics},
 month = {Jan},
 note = {Article, Formalized Mathematics. 20(1): 47-59 (2012)},
 pages = {47--59},
 title = {Z-modules},
 volume = {20},
 year = {2012}
}