1. Clarke, E.-A rare form of nystagmus. Trans. Ophthal. Soc. U.K., Vol. XVI, p. 327, 1896.
2. B.-A rare form of nystagmus;Grimsdale, H.;Ibid., Vol. XVI
3. E.-A rare form of nystagmts;Brewerton;Ibid., Vol. XXIII,1903
4. Nystagmus on covering one eye;Cunningham, J.F.;Proc. Roy. Soc. Med
5. III; sect, of neur;VII, Part;obhthal. and otol,1914