Bi, H., Fang, L.-Z., Feng, L., & Jing, Y. (2003). Hydrogen clouds before reionization: a lognormal model approach. The Astrophysical Journal, 598(1 Part 1), 1-12. Retrieved from http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v598n1/57186/brief/57186.abstract.html.