Author,Title,Edition,Publisher,Year,Series,Number,ISBN,ISSN,URL
"International School of Physics ""Enrico Fermi"" and Sachs, Rainer Kurt and Società italiana di fisica",General relativity and cosmology,,Academic Press,1971,"Rendiconti della Scuola internazionale di fisica ""Enrico Fermi""",,0123688477,,https://cir.nii.ac.jp/crid/1130000798370667904