Koval, Ya. M., and І. О. Федак. “Allocation of Polymictic Sandstones in a Complex Geological Section of Oil and Gas Wells of the Dnipro-Donetsk Depression”. Oil and Gas Power Engineering, no. 1(37), June 2022, pp. 7-14, doi:10.31471/1993-9868-2022-1(37)-7-14.