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"In the NB system, you should include a note (endnote or footnote) each time you use a source, whether through a direct quote, paraphrase, or summary. Footnotes will be added at the end of the page on which the source is referenced, and endnotes will be compiled at the end of each chapter or at the end of the entire document.
In either case, a superscript number corresponding to a note with the bibliographic information for that source should be placed in the text following the end of the sentence or clause in which the source is referenced."
Some teachers ask you to cite sources but want them placed at the bottom of the page as a footnote. If you need that, then copy the bibliography citation for that source and paste it in to your footnote at the bottom of your page.