1. Kolomensky, N.V.: General method of engineering and geological research, p. 344. Nedra, Moscow, Russia (1968)
2. Popov, I.V.: Engineering geology. USSR. Part V. Kazakhstan. Average Asia. State University Publishing House: Moscow, Russia, p. 431 (1974)
3. Engineering geology of the USSR, vol. 6. Kazakhstan. In: Dmitrovsky, V.I.(ed). Publishing house of Moscow University: Moscow, Russia, p. 296 (1977)
4. Popov, V.N.: Geotechnical problems of foundation engineering in conditions of activation of natural and man-made processes and ways to solve them: dissertation Doc. Tech. Sci. 05, 23.02. Astana, p. 270 (2004)
5. Britannica, T.: Editors of Encyclopaedia. Nur-Sultan. Encyclopedia Britannica, (2021). https://www.britannica.com/place/Nur-Sultan