@techreport{weko_20584_1, author = "高橋,千恵 and 横田,一正", title = "演繹データベースへの階層概念の導入", year = "1990", institution = "(財)日本情報処理開発協会, (財)新世代コンピュータ技術開発機構", number = "63(1990-DBS-078)", month = "jul" }