Eagles' kelly green throwback uniforms can return thanks to NFL alternate helmet rule change
NFL allows teams to wear throwback jerseys for three games in 2018, per report - Acme Packing Company
Here's all the new NFL uniforms and helmets for the 2023 season – NBC10 Philadelphia
Denver Broncos Unveil New “Snowcapped” White Alternate Helmets – SportsLogos.Net News
The Official Uni Watch 2021 NFL Season Preview - InsideHook
NFL 2023: New Uniforms, Helmets for 13 Teams
Arizona Cardinals unveil new uniforms for the 2023 season
The Steelers are unveiling new throwback uniforms but what will the be? - Behind the Steel Curtain
Buffalo Bills can wear throwback jerseys three times in 2018