@techreport{oai:kwansei.repo.nii.ac.jp:00026885,
 author = {新海, 哲哉 and 北村, 亮真 and Shinkai, Tetsuya and Kitamura, Ryoma},
 issue = {179},
 month = {May},
 title = {Product Line Strategy within a Vertically Differentiated Duopoly under Non-negativity Outputs Constraints},
 year = {2018}
}