Relativistic R-matrix calculations of photoionization cross sections of Cu XVIIIAvnindra K. Singh, Dishu Dawra, Mayank Dimri, Alok K. S. Jha and Man MohanEur. Phys. J. D, 73 5 (2019) 85DOI: https://doi.org/10.1140/epjd/e2019-90464-x