The Holmberg effect of Main galaxy pairs of the SDSS Data Release 4   (SDSS4)
  We have investigated the Holmberg effect of Main galaxy pairs of the SDSS Data Release 4 (SDSS4). It is found that except i-z color the color indices between the two components of Main galaxy pairs clearly have significantly larger correlation coefficients. Further analyses also show that the Holmberg Effect of galaxies not only depends on the color indices but also on the morphological type for two components of pairs. 
Deng Xin-Fa, Ma Xin-Sheng, He Con-Gen, Luo Cheng-Hong, He Ji-Zhou