The historian footnoted every primary source to clarify its provenance.

I added a footnote to clarify the statistic cited in the paragraph above.

Please footnote any statistics you cite in your report.

Before submitting the thesis, she carefully reviewed the footnotes to ensure every source was cited correctly.

The editor always footnotes controversial claims to provide context and sources.

Footnoting every source took longer than she expected, but it strengthened her argument.

The footnoter carefully checked each source before adding citations.

The footnoters argued that the author's claim needed more historical evidence.