@techreport{oai:kwansei.repo.nii.ac.jp:00029917,
 author = {新海, 哲哉 and 北村, 亮真 and Shinkai, Tetsuya and Kitamura, Ryoma},
 issue = {230},
 month = {Oct},
 title = {How Do the Relative Superiority of a High-quality Good and Cost Inefficiency between Firms Affect Product Lines in Multiproduct Firms?},
 year = {2021}
}