Lee Bennett Giacalone, J., Burgess, D., Schwartz, S. J., Ellison, D. C., & Bennett, L. (1997). Injection and acceleration of thermal protons at quasi-parallel shocks: a hybrid simulation parameter survey. Journal of Geophysical Research. Space Physics, 102(A9), 19789–19804. https://doi.org/10.1029/97JA01529