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 Great Britain. Monopolies and Mergers Commission,"Ulsterbus Limited and Citybus Limited : a report on bus services in Northern Ireland supplied by the undertakings : presented to Parliament by the Secretary of State for Trade and Industry by command of Her Majesty, June 1989",,H.M.S.O,1989,Cm,,0101069626,,https://cir.nii.ac.jp/crid/1130282270093337472