@techreport{weko_51287_1,
   author	 = "伊藤,昭",
   title	 = "自然な推論による拡張世界の回復　－デフォルト推論と拡張世界木－",
   year 	 = "1988",
   institution	 = "郵政省通信総合研究所",
   number	 = "83(1988-ICS-061)",
   month	 = "nov"
}