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Williams, E. J. (1931), "The Loss of Energy by β -Particles and Its Distribution between Different Kinds of Collisions", Proceedings of the Royal Society of London. Series A, 130 (813): 328–346, Bibcode:1931RSPSA.130..328W, doi:10.1098/rspa.1931.0008
Williams, E. J. (1931), "The Loss of Energy by β -Particles and Its Distribution between Different Kinds of Collisions", Proceedings of the Royal Society of London. Series A, 130 (813): 328–346, Bibcode:1931RSPSA.130..328W, doi:10.1098/rspa.1931.0008