Iron Man's Hulk Cameo is Part of a Bigger, Secret Story

Tony Stark has history with Thunderbolt Ross.
Robert Downey Jr.'s Tony Stark had a cool cameo in The Incredible Hulk - and tie-in comics provide the context.

Marvel Just Gave Iron Man's Armor a Major Upgrade

Iron Man's Hulk Cameo is Part of a Bigger, Secret Story

Mark XLIV Iron Man Armor, Marvel Cinematic Universe Wiki

MCU Phase 5 Confirms Another Avenger Is Repeating Iron Man's Curse

Who do you want to see pop up in Avengers: Secret Wars? : r/Avengers

Archive ScreenRant

Anthony Stark (Earth-616), Marvel Database

MIGHTY MARVEL MASTERWORKS: THE INCREDIBLE HULK VOL. 3 - LESS THAN

Iron Man, Marvel Cinematic Database

Comics Film 'Iron Man' Was a Risky and Bold Adventure for Marvel

Is That Bruce Banner In The Hulkbuster Armor?

Incredible Hulk, Creators, Stories, TV Show, & Films

What are Marvel's Ten Rings? Comic Origins and Powers Explained