The majority of the early surveys found results which seemed to confirm Freeman's results, although with a wider spread -

• Yoshizawa and Wakamatsu (1975) found 24 galaxies with µ(0) = 21.28 +\- 0.71 mag arcsec;

• Schweitzer (1976) found 6 galaxies with µ(0) = 21.67 +\- 0.35 mag arcsec;

• Burnstein (1979) surveyed 12 S0 galaxies and found them to have µ(0) = 20.1 mag arcsec through 22.1 mag arcsec.