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
"Essen, A. R. P. van den (Arnoldus Richardus Petrus van den) and Levelt, A. H. M. (Antonius Henricus Maria)",Irregular singularities in several variables,,American Mathematical Society,1982,Memoirs of the American Mathematical Society,,0821822705,,https://cir.nii.ac.jp/crid/1130282270462197760