1. Poton’e, G., Kazarinovoi, E.V., and Grave, N.N., Proiskhozhdenie kamennogo uglya i drugikh kaustobiolitov (Origin of Bituminous Coal and Other Caustobioliths), Shebunin, F.A. and Krishtofovich, A.N., Eds., Leningrad: Glav. Red. Gorno-Toplivnoi Lit-ry, 1934.
2. Geologicheskii slovar’. V 2 t (Geological Dictionary in Two Volumes), Paffengol’ts, K.N., Ed., Moscow: Nedra, 1978, 2nd ed.
3. Dmitrienko, A.A. and Isayeva, E.R., Structural aspects of the coalification of organic materials, Coke Chem., 2019, vol. 62, no. 12, pp. 552–555. https://doi.org/10.3103/S1068364X19120044
4. Volkova, I.B. and Bogdanova, M.V., Scattered organic substance of black-shale depositions and method for their study, Problemy osadochnoi geologii dokembriya (Problems of Sedimentary Geology of Precambrian), Moscow: Nauka, 1981, vol. 7, no. 2, p. 260.
5. Silaev, V.I., Lyutoev, V.P., Petrovskii, V.A., and Khazov, A.F., A study of naturally occurring carbonaceous substances and some of their synthetic analogues by the method of Raman spectroscopy, Mineralogicheskii Zh., 2013, vol. 35, no. 3, pp. 33–47.