Gao, L., Loeb, A., Peebles, P. J. E., White, S. D. M., & Jenkins, A. (2004). Early Formation and Late Merging of the Giant Galaxies. The Astrophysical Journal, 614(1 Part 1), 17-25. Retrieved from http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v614n1/59567/brief/59567.abstract.html.