RT Journal Article SR Electronic T1 Preservation of Ophthalmic Solutions JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 174 OP 177 DO 10.1136/bjo.39.3.174 VO 39 IS 3 A1 M. L. Frith A1 S. E. Wright YR 1955 UL http://bjo.bmj.com/content/39/3/174.abstract AB