Hao, H., Elvis, M., Bongiorno, A., Zamorani, G., Merloni, A., Kelly, B. C., et al. (2013). A quasar–galaxy mixing diagram: quasar spectral energy distribution shapes in the optical to near-infrared. Monthly Notices of the Royal Astronomical Society, 434(4), 3104-3121. doi:10.1093/mnras/stt1228.