Dobson, V., Clifford-Donaldson, C. E., Miller, J. M., Garvey, K. A., & Harvey, E. M. (2009). A comparison of Lea Symbols versus ETDRS letter distance visual acuity in a population of young children with a high prevalence of astigmatism.

Dobson, Velma, Candice E. Clifford-Donaldson, Joseph M. Miller, Katherine A. Garvey, i Erin M. Harvey. A Comparison of Lea Symbols Versus ETDRS Letter Distance Visual Acuity in a Population of Young Children With a High Prevalence of Astigmatism. 2009.

Dobson, Velma, et al. A Comparison of Lea Symbols Versus ETDRS Letter Distance Visual Acuity in a Population of Young Children With a High Prevalence of Astigmatism. 2009.