Hughes, MA, Gwilliam, RM, Homewood, K, Gholipour, B, Hewak, DW, Lee, TH, Elliott, SR, Suzuki, T, Ohishi, Y, Kohoutek, T, Curry, RJ, "On the analogy between photoluminescence and carrier-type reversal in Bi- and Pb-doped glasses", Optics Express,