Electron impact excitation for He-like ions with Z = 20–42R. Si, S. Li, K. Wang, X. L. Guo, Z. B. Chen, J. Yan, C. Y. Chen, T. Brage and Y. M. ZouA&A, 600 (2017) A85DOI: https://doi.org/10.1051/0004-6361/201630027
