O.S. Karger, A. Knetsch, G. Wittig, D.L. Bruhwiler, G. Pretzler, A. Murokh, G. Andonian, J. Smith, A. Deng, Y. Xi, J.B. Rosenzweig, B. Hidding, D.A. Jaroszynski, G.G. Manahan and Z. Sheng, “Ultrahigh brightness bunches from hybrid plasma accelerators,” presented at Proc. Int. Part. Accel. Conf. (Richmond, May 2015).