Krishna, V., et al. “Refractive Index of Ternary Liquid Mixtures of Toluene, Cyclohexane, Carbon Tetrachloride and Benzene at 298.15 K”. Asian Journal of Chemistry, vol. 4, no. 1, Mar. 2010, pp. 120-7, https://asianpubs.org/index.php/ajchem/article/view/25011.