RT Journal Article SR Electronic T1 Normal retinal vascular pattern. Arteriovenous ratio as a measure of arterial calibre. JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 21 OP 40 DO 10.1136/bjo.50.1.21 VO 50 IS 1 A1 Stokoe, N. L. A1 Turner, R. W. YR 1966 UL http://bjo.bmj.com/content/50/1/21.abstract AB