A. A. Akhmadeev, A. R. Gainutdinov, M. A. Khamadeev, M. Kh. Salakhov, “Determination of porosity of silica microparticles by using the refractive index matching method”, Optics and Spectroscopy, 128:9 (2020), 1277–1280; Optics and Spectroscopy, 128:9 (2020), 1388–1392
