H. S. Mahdi, “The Bimodal Color Distribution of Galaxies at Redshift of z=0-0.15 from the Sloan Digital Sky Survey (SDSS)”, Al-Mustansiriyah Journal of Science, vol. 30, no. 2, pp. 52–59, Sep. 2019, doi: 10.23851/mjs.v30i2.574.