When to Use Footnotes 

When to use footnotes for citations of quotations, summaries, paraphrases, and facts and statistics from published or online sources. In CMOS, writers use footnotes to cite secondary sources and many primary sources, but also use parenthetical in-text citation for certain primary sources such as the Bible, classical works, poems, and plays because these works have their own stable reference numbers, such as the Bible's chapter and verse or a poem's line numbers. For example: "In the beginning was the Word" (John 1:1 KJV). See Turabian, chapter 17 on footnote style, chapter 19.8 on classical citation, and chapter 25 on introducing and modifying quotations. Consider contacting your local writing center.