A. A. Bukharaev, A. V. Kazakov, R. A. Manapov, I. B. Khaibullin, “Magnetic and optical properties of $\mathrm{SiO}_{2}$ surface layers containing small $\alpha$-$\mathrm{Fe}$ ferromagnetic particles produced by ion bombardment”, Fizika Tverdogo Tela, 33:4 (1991), 1018–1026
