Beuken, J.-M., Pierson, E., & Bertrand, P. (1989). Simulation of the Trajectory-dependent Neutralization Probability of Low-energy He+ Scattered From Nacl. Surface Science, 223(1-2), 201-212. https://doi.org/10.1016/0039-6028(89)90734-6 (Original work published 1989)