Mirzayeva, G., and V. Rzayeva. “Analysis Free Oscillations of a Non-Homogeneous Pipe along’s Thickness and Length, Taking into Account the Resistance of the External Environment”. Technology Audit and Production Reserves, vol. 5, no. 1(55), Oct. 2020, pp. 24-27, doi:10.15587/2706-5448.2020.213475.