European American Football: Playing in Pro Football Leagues Overseas
Awesome assembly Central European Football League - CEFL
American Football in Europe
NFL Goes International: Takes Europe and Mexico - The New Paltz Oracle
NFL floats wild idea of possibly putting four teams in Europe as part of major international expansion
The rising popularity of American Football in Germany – GermanyinUSA
Study reveals Europe's favourite NFL teams
N.F.L. Pulls the Plug on Its League in Europe - The New York Times
Why American Football is number one in the US and an enigma for the rest of us?, by Alexis Colmant, sportopath
The NFL Returns to the Raucous German Fan Base It Left Behind - The Ringer