Hu, S.Z., et al. “Synthesis, Characterization and Photocatalytic Activity of Anatase-Brookite- Rutile Composite TiO2 Nanocrystals Prepared in H2O Alcohol System”. Asian Journal of Chemistry, vol. 24, no. 3, Dec. 2011, pp. 1135-40, https://asianpubs.org/index.php/ajchem/article/view/8726.