Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) RAMOS S.,First stage coloration of alkali halides doped with M^<2+> impurities that change their valence state by irradiation.,Solid State Communications.,,,1985,56,,435-440,https://cir.nii.ac.jp/crid/1570572701702778752,