@techreport{oai:tsukuba.repo.nii.ac.jp:00037087,
 author = {IZUNAGA, Yoichi and MATSUI, Tomomi and YAMAMOTO, Yoshitsugu and 山本, 芳嗣},
 month = {Feb},
 title = {A doubly nonnegative relaxation for modularity density maximization},
 year = {2016}
}