Phillips, G.C., et al. “Natural Modulation of High Frequency Ion Source Beams”. Nuclear Instruments, vol. 3, no. 1, 1958, pp. 43-44, https://doi.org/10.1016/0369-643x(58)90047-1.
Phillips, G., Paul, E., Ferguson, A., Whitehead, A., Grjebine, T., Moreau, R., & Olkowsky, B. (1958). Natural modulation of high frequency ion source beams. Nuclear Instruments, 3(1), 43-44. https://doi.org/10.1016/0369-643x(58)90047-1
Phillips G, Paul E, Ferguson A, Whitehead A, Grjebine T, Moreau R, et al. Natural modulation of high frequency ion source beams. Nuclear Instruments. 1958;3(1):43-4.