@mastersthesis{oai:tsukuba.repo.nii.ac.jp:00032969,
 author = {工藤, 剛},
 month = {},
 note = {2013},
 school = {筑波大学, University of Tsukuba},
 title = {特許分類の共起を用いた技術動向調査手法に関する研究},
 year = {2014}
}