Yu. A. Rozhnova, S. V. Kuznetsov, A. A. Luginina, V. V. Voronov, A. V. Ryabova, D. V. Pominova, R. P. Ermakov, V. A. Usachev, N. E. Kononenko, A. E. Baranchikov, V. K. Ivanov, P. P. Fedorov New Sr1-x-yRx(NH4)yF2+x-y (R = Yb, Er) solid solution as precursor for high efficiency up-conversion luminophor and optical ceramics on the base of strontium fluoride. Materials Chemistry Physics. 2016. v.172. p.150-157. doi:10.1016/j.matchemphys.2016.01.055