Natural waves in a spatial viscoelastic cylinder with a radial crack Nasriddin Kuldashov, Zafar Boltaev, Mirqosim Xudoyberdiyev, Uktam Juraev and Tulkin Ruziyev E3S Web Conf., 417 (2023) 06014 Published online: 21 August 2023 DOI: 10.1051/e3sconf/202341706014