“Study of R -Molar Ratio Effect on the Transformation of Tetraethylorthosilicat Precursor to Gels in Sol-Gel Technique”. Baghdad Science Journal 6, no. 3 (September 6, 2009): 590–595. Accessed January 23, 2025. https://bsj.uobaghdad.edu.iq/index.php/BSJ/article/view/1020.