Best relievers in Cubs history

A Decade of Cubs Closers. By: Alex Patt, by Alex Patt, Wrigley Rapport

Cubs' Justin Steele, six relievers no-hit Padres in spring training - ESPN

Best relievers in White Sox history

Pitchers' Swings, and Their Throws, Keep Cubs Rolling Past Giants - The New York Times

Report: Philadelphia Phillies to Acquire Chicago Cubs Reliever David Robertson - Sports Illustrated Inside The Phillies

The MLB Relief Pitcher Championship Belt - The Ringer

Indians, Cubs benefiting from deadline trades with Yankees – New York Daily News

MLB free agency: 7 best relief pitchers still available

The 1906-10 Chicago Cubs: The Best Team in National League History – Society for American Baseball Research

Chicago Cubs all-time lists of the best and worst - Cubbies Crib