1977, Kormendy found two galaxies with 
(0)
=22.78 & 22.68 B
. He claimed the galaxies were confirmation there exist
faint disks which selection effects had screened.
1985, Disney & Phillipps examined 500 galaxies from the Second Reference Catalog of Bright Galaxies (deVaucouleurs, 1976) and found no correlation between the central surface brightness and galaxy type, color (B-V), and absolute magnitude. Thus they concluded surface brightness could not be a constant value, and selection effects must play an important role in our knowledge of galaxies.
