1. Scheiner, C.: Quoted by Marg, E., and Morgan, M. W., Jr.12
2. Weber, E. H.: Quoted by Marg, E., and Morgan, M. W., Jr.12
3. Weber, E. H. Quoted by Marg, E., and Morgan, M. W., Jr.12
4. de Ruiter, G. C. P.: Quoted by Marg, E., and Morgan, M. W., Jr.12
5. On the Anomalies of Accommodation and Refraction of the Eye;Donders,1864