1. Balaram, V., Geosci. Front., 2019, vol. 10, no. 4, pp. 1285–1303. https://doi.org/10.1016/j.gsf.2018.12.005
2. Korovin, S.S., Zimina, G.V., Reznik, A.M., Bukin, V.I., and Kornyushko, V.F., Redkie i rasseyannye elementy. Khimiya i tekhnologiya (Rare and Less Common Elements: Chemistry and Technology), Moscow: Mosk. Inst. Stali Splavov, vol. 1, 1996, p. 12.
3. Vinogradov, A.P., Geokhimiya, 1956, no. 1, pp. 6–52.
4. Gol’dberg, I.S., Prirodnye bitumy SSSR (zakonomernosti formirovaniya i razmeshcheniya) [Natural Bitumens of the USSR (Fundamental Aspects of Formation and Distribution)], Leningrad: Nedra, 1982.
5. Sukhanov, A.A. and Petrova, Yu.E., Neftegaz. Geol., Teor., Prakt., 2008, vol. 3, no. 2, pp. 1–11.