TY - JOUR T1 - Cobalt Glass in Refraction Work JF - British Journal of Ophthalmology JO - Br J Ophthalmol SP - 236 LP - 237 DO - 10.1136/bjo.4.5.236-a VL - 4 IS - 5 A2 - , Y1 - 1920/05/01 UR - http://bjo.bmj.com/content/4/5/236.2.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -