Jiamusi pulsar observations - III. Nulling of 20 pulsars P. F. Wang, J. L. Han, L. Han, B. Y. Cai, C. Wang, T. Wang, X. Chen, D. J. Zhou, Y. Z. Yu, J. Han et al. (5 more) A&A, 644 (2020) A73 Published online: 02 December 2020 DOI: 10.1051/0004-6361/202038867