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 "Feltrin, Guglielmo",Positive solutions to indefinite problems : a topological approach,,Birkhäuser,2018,Frontiers in mathematics,,9783319942377,,https://cir.nii.ac.jp/crid/1130000798045459200