The physical properties of γ-ray-quiet flat-spectrum radio quasars: why are they undetected by Fermi-LAT? - Deng, Xue-Jiao; Xue, Rui; Wang, Ze-Rui; Xi, Shao-Qiang; Xiao, Hu-Bing; Du, Lei-Ming; Xie, Zhao-Hua (Monthly Notices of the Royal Astronomical Society, 2021)