In Chicago Notes & Bibliography style, you tell the reader that you have used a source by placing a superscript number (a number typed above the line) at the end of the sentence in which you refer to a source. You then give the reader information about the source in a correspondingly numbered note. Notes are placed either at the bottom of the page on which they are referred (footnotes) or listed at the end of the paper (endnotes).
A Manual for Writers of Research Papers, Theses, and Dissertations by