Subscribe to The Chicago Manual of Style Online
Citation, Documentation of Sources
Q. When using the same five sources throughout the same paper, do I create a new endnote (using a new number) throughout the paper (1, 2, 3, 4, 5, etc.)? For example, if my paper has twenty-two citations, will I use endnotes 1–22? Or do I just refer to the same five numbers throughout the paper?
A. You will need all twenty-two numbers, although it’s fine to shorten a citation after you’ve given it once in full. The other method is used mainly for charts and tables, where you can recycle a single note number every time it applies.