NFL hires Terri Valenti, its first female replay official
The Game-Changing Women of the N.F.L. - The New York Times
NFL gets first female replay official, 8 new officials
The story behind the XFL's female officials
Official (gridiron football) - Wikipedia
Sarah Thomas 1st female on-field NFL playoff game official
SN source: NFL to add another female to officiating department
Sarah Thomas is first female on-field official in NFL playoff history – New York Daily News
AP source: Second female official hired by NFL
Sarah Thomas is first woman to officiate an NFL playoff game
Sarah Thomas makes history by becoming first woman on-field official in NFL playoff game