W. A. A. Twej, A. M. Alattar, M. Drexler, and F. M. Alamgir, “Tuned optical transmittance in single-step-derived silica aerogels through pH-controlled microstructure”, Int. Nano Lett., vol. 7, no. 4 (December 2017), Sep. 2017, doi: 10.1007/s40089-017-0216-0.