Batting helmet - Wikipedia
Inside the legend of John Olerud, college baseball's two-way star - ESPN
John Olerud - Wikipedia
Acid Flashback Friday: John Olerud's Helmet
A gentleman and a slugger - Sports Illustrated Vault
Why do MLB players wear helmets with only one ear flap? - Quora
Why don't MLB players wear helmets with two ear protectors? - Quora
Ex-Jays Olerud, Barfield enter Canadian Hall of Fame at last
Eddie Vedder wore a batting helmet to throw a first pitch for the Mariners' Pearl Jam Night
This All-Star Game had plenty to remember but nothing that was unforgettable
Govs begin regular season's final month at UCA - Austin Peay State University Athletics
Remembering John Olerud - SoDo Mojo
Rozner: Olerud tale gives hope for Farquhar family
Danny Farquhar fights for life as friends pray for White Sox pitcher