Electron collisional excitation of argon-like Ni XI using the Breit-Pauli R-matrix method - Breit-Pauli R-matrix calculation for electron impact excitation of Ni10+N. Verma, A. K.S. Jha and M. MohanEur. Phys. J. D, 42 2 (2007) 235-241DOI: https://doi.org/10.1140/epjd/e2007-00030-0