review of collisional ionization for light elements
extensive discussion of electron collisional ionization
The effect of ionization on the populations of excited levels of C IV and C V in
tokamak edge plasmas
Lawson, K. D., Coffey, I. H., Aggarwal, K. M., Keenan, F. P., & Contributors, J.-E.
2013, Journal of Physics B Atomic Molecular Physics, 46, 035701