著者名,書名,版表示,出版者名,出版年,シリーズ名,番号,ISBN,ISSN,URL
"Poulsen, Birgit Truust",The Medvedev lattice of degrees of difficulty,,"[Matematisk Institut, Aarhus Universitet]",1970,Various publications series,,,,https://cir.nii.ac.jp/crid/1130000797347020928