Progress on collisionally pumped optical-field-ionization soft x-ray lasers by Sebban, S, Mocek, T, Bettaibi, I, Cros, B, Maynard, G, Butler, A, Gonzalves, A, McKenna, C, Spence, D, Hooker, S, Upcraft, L, Breger, P, Agostini, P, le Pape, S, Zeitoun, P, Valentin, C, Balcou, P, Ros, D, Kazamias, S, Klisnick, A, Jamelot, G, Rus, B, Wyart, J