Provenance of GRGs larger than 3 Mpc. Counterclockwise from the top, the categories are as follows: LOFAR publ.: GRGs found and published from LoTSS (Dabhade et al. 2020b; Oei et al. 2023a; Mostert et al. 2023), LoTSS Deep (Simonte et al. 2024; Bondi et al. 2024), and LoTSS DR2 new, which refers to our own discoveries from LoTSS DR2 images; the National Radio Astronomy Observatory (NRAO) VLA Sky Survey (NVSS, Condon et al. 1998) and Faint Images of the Radio Sky at Twenty-cm (FIRST, Becker et al. 1995),; recent surveys with the Australian Square Kilometre Array Pathfinder (ASKAP, McConnell et al. 2020; Norris et al. 2021); the Sydney University Molonglo Sky Survey (SUMSS, Mauch et al. 2003); the Murchison Widefield Array surveys (MWA, Offringa et al. 2016; Hurley-Walker et al. 2017, 2022; Lynch et al. 2021); the Westerbork Northern Sky Survey (WENSS, Rengelink et al. 1997), obtained with the Westerbork Synthesis Radio Telescope (WSRT); and the MeerKAT MALS DR2 (Wagenveld et al. 2024).