1. Petrology of the Granitovo pluton;Vergilov;Bull. Geol. Inst., série Géochim., Miner. and Petrogr.,1968
2. E. Aleksiev I. Kotorova G. Panajotov 1978 FX-détermination de Rb, Sr, Ba, Zr, Ti, Mn, V et Cr dans les roches magmatiques
3. Contib;Emmermann;Mineral. Petrol.,1975
4. Photometric determination of the sum of rare earths in ores and rocks.;Zaikovsky;Y.A. Chim.,1959