Long-term stability estimation of ensemble pulsar timescales with NICER observations H. F. Sun, D. K. Yao, Y. Hao, Z. W. Deng, F. Chen, S. H. Zhao, Q. Y. Zhou, L. R. Shen, X. P. Li and W. M. Bao A&A, 698 (2025) A228 Published online: 17 June 2025 DOI: 10.1051/0004-6361/202452141