Umpire (baseball) - Wikipedia
Umpire (baseball) - Wikipedia
10 Secrets of MLB Umpires
Atlantic League introduces 'robot umpires' to baseball - The Washington Post
MLB umpire salary: How much do they take home on average?
MLB: Umpire Hernandez blew calls, losing World Series job
Eastern League's Matsuda working to become first major league umpire from Japan
MLB, Official Information, Umpires
The MLB Umpires Association is a flawed and opaque organization - Bleed Cubbie Blue
MLB umpire rankings: Pat Hoberg is baseball's most accurate ump
MLB asking umpires for more checks of pitchers for sticky substances