A brief history of roster sizes in the NFL - Hogs Haven
NFL hopes to reduce head injuries with helmet experiment
NFL, players agree not to play preseason games in 2020
NFL canceling 2020 preseason, agrees to reduced training camp rosters
2020 NFL training camp battles to watch: Wide receiver, NFL News, Rankings and Statistics
2023 Detroit Lions 53-man roster projection: Pre-training camp edition - Pride Of Detroit
NFL Health and Safety Fact Sheet
Safe to say nobody at Patriots camp is missing two-a-days - The Boston Globe
Report: Preseason canceled, camp rosters expected to be 80 players
N.F.L. Trims Early Preseason Game and Prepares for Training Camps - The New York Times