Evidence for Reionization at [ITAL][CLC]z[/CLC][/ITAL] ∼ 6: Detection of a Gunn-Peterson Trough in a [ITAL][CLC]z[/CLC][/ITAL] = 6.28 QuasarR. H. Becker, Donald G. York, Xiaohui Fan et al.|The Astronomical Journal|2001Cited by 941