Biases in galaxy cluster velocity dispersion and mass estimates in the small Ngal regime A. Ferragamo, J. A. Rubiño-Martín, J. Betancort-Rijo, E. Munari, B. Sartoris and R. Barrena A&A, 641 (2020) A41 Published online: 04 September 2020 DOI: 10.1051/0004-6361/201834837