1. Kolodyazhnyi, A.V., Koval’chuk, T.N., Korovin, Yu.V., and Antonovich, V.P., Metody Ob’ekty Khim. Anal., 2006, vol. 1, no. 2, p. 90.
2. Khadzhiev, S.N. and Shpirt, M.Ya., Mikroelementy v neftyakh i produktakh ikh pererabotki (Trace Elements in Oils and Products of Their Processing), Moscow Nauka, 2012.
3. Sukhanov, A.A. and Petrova, Yu.E., Neftegaz. Geol. Teor. Prakt., 2008, vol. 3, no. 2. http://www. ngtp.ru/rub/9/23_2008.pdf. Cited October 10, 2016.
4. Yashchenko, I.G., Izv. Tomsk. Politekh. Univ., 2012, vol. 321, no. 1, p. 105.
5. http://www.ngtp.ru/rub/9/56_2012.pdf. Cited October 10, 2016.