Observation of laser power amplification in a self-injecting laser wakefield accelerator - Streeter, M; Kneip, S; Bloom, M; Bendoyro, RA; Chekhlov, O; Dangor, AE; Doepp, A; Hooker, CJ; Holloway, J; Jiang, J; Lopes, N; Nakamura, H; et al. (Physical Review Letters, 2018)