Proper normal waves in a two-layer tube taking into account the rheological properties of materialsIsmoil Safarov, Mukhsin Teshaev, Tulkin Ruziev, Matlab Ishmamatov and Nurillo KulmuratovE3S Web Conf., 417 (2023) 06003DOI: https://doi.org/10.1051/e3sconf/202341706003