27. Guggenheim, J. A., Pong-Wong, R., Haley, C. S., Gazzard, G., and Saw, S. M. (2007) Correlations in refractive errors between siblings in the Singapore Cohort Study of Risk factors for Myopia. Br J Ophthalmol 91, 781-784

27. Guggenheim, J. A., Pong-Wong, R., Haley, C. S., Gazzard, G., and Saw, S. M. (2007) Correlations in refractive errors between siblings in the Singapore Cohort Study of Risk factors for Myopia. Br J Ophthalmol 91, 781-784