Red giant branch bump brightness in 7 metal-poor globular clusters obtained with GAIA DR2. - Song, Fen; Yuan, Zunli; Li, Yan; Wu, Xuchao; Pietrinferni, Adriano; Poon, Helen; Wu, Tao; Nie, Jundan; Song, Hanfeng; Han, Cheng; Yang, Ye; Li, Yuxuan; et al. (Astrophysics & Space Science, 2022)