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
"Catholic Church. Pope ( : Gregory VII) and Cowdrey, H. E. J. (Herbert Edward John)",The Epistolae vagantes of Pope Gregory VII,,Clarendon Press,1972,Oxford medieval texts,,0198222203,,https://cir.nii.ac.jp/crid/1130282273119373312