Question: How many decades did the company, which produced The Flintstones, dominate American television animation?
Sentence (from "Hanna-Barbera"): Hanna-Barbera Productions, Inc. (simply known as Hanna-Barbera and also referred to as H-B Enterprises, H-B Production Company and Hanna-Barbera Cartoons, Inc.) was an American animation studio that dominated American television animation for over three decades in the mid 20th century.
Relevant evidence: Yes