Alexander, D., Chary, R., Pope, A., Bauer, F., Brandt, W., Daddi, E., …Reddy, N. (2008). Reliable identification of Compton-thick quasars at z~2 : Spitzer mid-infrared spectroscopy of HDF-oMD49. Astrophysical Journal, 687(2), 835-847. https://doi.org/10.1086/591928