Hong Chen, Ai, and Nurulain Muhamad. “Contrast Ratios, Colour Elements, and Polarities in Visual Acuity Measurements”. International Journal of Engineering and Technology 7, no. 3.11 (July 21, 2018): 89–93. Accessed May 12, 2025. https://mail.sciencepubco.com/index.php/IJET/article/view/15936.