Citation for Introduction
Citation styles are based on the Chicago Manual of Style, 15th Ed., and the MLA Style Manual, 2nd Ed..
MLA
Suggs, M. Jack , Katharine Doob Sakenfeld and James R. Mueller. "The Revelation of John." In The Oxford Study Bible. Oxford Biblical Studies Online. 21-Jan-2021. <http://www.oxfordbiblicalstudies.com/article/book/obso-9780195290004/obso-9780195290004-chapterFrontMatter-81>.
Chicago
Suggs, M. Jack , Katharine Doob Sakenfeld and James R. Mueller. "The Revelation of John." In The Oxford Study Bible. Oxford Biblical Studies Online, http://www.oxfordbiblicalstudies.com/article/book/obso-9780195290004/obso-9780195290004-chapterFrontMatter-81 (accessed 21-Jan-2021).