. "\"The chemical reactions and pathways resulting in the formation of any purine ribonucleoside, a nucleoside in which purine base is linked to a ribose (beta-D-ribofuranose) molecule.\" [GOC:ai]" . . "purine ribonucleoside biosynthetic process" . "purine ribonucleoside anabolism" . "purine ribonucleoside biosynthesis" . "purine ribonucleoside formation" . "purine ribonucleoside synthesis" . . . .