For citations:
Yasyrkina D.S., Kuznetsov S.V., Ryabova A.V., Pominova D.V., Voronov V.V., Ermakov R.P., Fedorov P.P. Dependence of quantum yield of up-conversion luminescence on the composition of fluorite-type solid solution NaY1-x-yYbxEryF4. Nanosystems: Physics, Chemistry, Mathematics. 2013;4(5):648-656.