Discovery of a thin lithium plateau among metal-poor red giant branch stars A. Mucciarelli, L. Monaco, P. Bonifacio, M. Salaris, M. Deal, M. Spite, O. A. Richard and R. Lallement A&A, 661 (2022) A153 Published online: 26 May 2022 DOI: 10.1051/0004-6361/202142889