Changes in 1970 Made Wrigley Field 'Friendly Confines' - Central Park Communications

Football in baseball stadiums

New Cubs explain why it truly is so 'different' at Wrigley Field - Marquee Sports Network

Wrigley Field renovations could mean more football at Friendly Confines - Ballpark Digest

Why don't baseball stadiums have retractable roofs? - Quora

What is the difference between a baseball ballpark and stadium? - Quora

Friendly Confines still a baseball mecca

Chicago Cubs Baseball: 1960s, 1970s & 1980s - HubPages

History of Wrigley Field - Wikipedia

Central Park Communications - Historical commentary, books, and consulting

Richard Rothschild: It's time to get rid of Wrigley Field - Sports Illustrated

Do any baseball stadiums besides Wrigley Field have rooftop bleachers? - Quora

Wrigley Field Fills Fans With Reverence, Even if It Looks a Bit Less Friendly - The New York Times

Wrigley Field : A Celebration of the Friendly Confines: Jacob, Mark, Green, Stephen, Banks, Ernie: 9780071385633: : Books

Wrigley100 -- Chicago Tribune