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 "Okecha, Stephen A.",Nigeria's foreign policy: a science-based appraisal,,The Nigerian Institute of International Affairs,1989,Lecture series (Nigerian Institute of International Affairs),,,,https://cir.nii.ac.jp/crid/1130282270413844992