Fallout New Vegas started life as Fallout 3 DLC

Bethesda was too busy with Skyrim to work on Fallout New Vegas, so turned it into a full game and gave it to Obsidian

A visual comparison of the amount of quests in fallout 3 compared to new vegas : r/Fallout

The Videogame Corner: Fallout 3

What is the best DLC for Fallout: New Vegas? - Quora

Music of the Fallout series - Wikipedia

Fallout: New Vegas – Honest Hearts DLC – Review

Fallout: New Vegas add-ons, Fallout Wiki

Fallout 3 - Wikipedia

Fallout: New Vegas – Dead Money DLC is more like deadweight

Which Fallout New Vegas DLC is the easiest, and the hardest? - Quora

25 Strange Things That Happened Between Fallout 3 And New Vegas

10 Best Fallout DLC, Ranked