A. Knetsch, O. Karger, Z.-M. Sheng, G. Xia, D. Jaroszynski, B. Hidding, A. Deng, D.L. Bruhwiler, G. Wittig, Y. Xi, G.G. Manahan, S. Jamison and J. Smith, “Ultra-low emittance electron beams from density downramp assisted Trojan Horse PWFA,” presented at the Advanced Accel. Concepts Workshop (National Harbor, Aug. 2016).