1 - SDSS
2 - UZC
4 - Papovich - Hectospec
8 - Marleau
16 - Lacy et al. (2007)
32 - Lacy et al. (2013)
64 - Yan et al. (2007)
128 - Sajina et al. (2008)
256 - Yan and Choi Keck (see Choi 2006/11), courtesy of Sajina catalogue in M. Vaccari catalogue
512 - NED sources in M. Vaccari catalogue