Green, J. (., & Ewing, A. E. Optotypes, consisting of test-letters and pictographs for measuring the acuteness of vision. U.S.A: [s.n.].
Chicago Style CitationGreen, John (1835-1913), and Arthur Eugene Ewing. Optotypes, Consisting of Test-letters and Pictographs for Measuring the Acuteness of Vision. U.S.A: [s.n.].
MLA CitationGreen, John (1835-1913), and Arthur Eugene Ewing. Optotypes, Consisting of Test-letters and Pictographs for Measuring the Acuteness of Vision. U.S.A: [s.n.].
Warning: These citations may not always be 100% accurate.