@phdthesis{oai:tsukuba.repo.nii.ac.jp:00021209,
 author = {Nakayama, Akira},
 month = {},
 note = {1989},
 school = {筑波大学, University of Tsukuba},
 title = {Studies on network optimization problems : maximum balanced flow and minimum cost flow problems},
 year = {1990}
}