Liu SY, Trope GE, Buys YM, El-Defrawy SR, Khan AM, Jin YP. Visual impairment and the Ontario disability support program. Can J Ophthalmol. 2020 Jun;55(3):212-20. doi: 10.1016/j.jcjo.2019.12.009
Glass RL, Rothman KJ, Espinal F, Velez H, Smith NJ. Prevalence of human dental caries and water-borne trace metals. Arch Oral Biol. 1973 Sep;18(9):1099-104. doi: 10.1016/0003-9969(73)90083-6