Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Sugiyama A,Theory of valency effect of impurity atoms on hardening of alloys,Journal of the Physical Society of Japan,00319015,Tokyo : Physical Society of Japan,1966-10,21,10,1873-1880,https://cir.nii.ac.jp/crid/1522825130656044672,