A new look at the isotropy of narrow line emission in extragalactic   radio sources
  We undertake a quantitative investigation, using Monte Carlo simulations, of the amount by which quasars are expected to exceed radio galaxies in optical luminosity in the context of the `receding torus' model. We compare these simulations with the known behaviour of the [O III] 5007 and [O II] 3727 emission lines and conclude that [O III] is the better indicator of the strength of the underlying non-stellar continuum. 
Chris Simpson