Eecen, P. J., Schep, T. J., & Tulupov, A. V. (1996). Spectral dynamics of a collective free electron maser. Nuclear Instruments & Methods in Physics Research Section a-Accelerators Spectrometers Detectors and Associated Equipment, 375, 190-193. https://doi.org/10.1016/0168-9002(95)01363-6 (Original work published)
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