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
"Friedman, Avner",On the properties of the coefficients of linear elliptic systems determined from the properties of the solutions,,"Dept. of Mathematics, University of California",1957,Technical report,,,,https://cir.nii.ac.jp/crid/1130282270098943744