MLB umpire job responsibilities
Umpire (baseball) - Wikipedia
Perspectives: Baseball umpires spur litigation in Minnesota – Minnesota Lawyer
MLB And Umpires: Inside the MLBUA - Dodger Yard
Are MLB umpires ruining the sport of baseball? - Quora
Worcester Red Sox are preparing for robotic ball-strikes system coming
MLB will see 10 rookie umps replace veterans as position faces more changes, challenges than ever - The Athletic
In Defense of Umpires: Why Complaints About MLB's 'Ump Show' Problem Miss the Mark, News, Scores, Highlights, Stats, and Rumors
Hazards of the Job: Umpire Injury, Told by Those Who Witnessed It
MLB umpire job responsibilities
Commentary: Major-league ump Ed Rapuano backs Pope John Paul II