Sapronov, O. O., et al. “Polymeric Materials Based on Epoxy Oligomer DER-331 and Hardeners of Different Physical and Chemical Nature for Repairing of Gas Production Equipment”. JOURNAL OF HYDROCARBON POWER ENGINEERING, vol. 7, no. 2, Dec. 2020, pp. 54-60, doi:10.31471/2311-1399-2020-2(14)-54-60.