Rumor Guide - Who Designed Super Saiyan 4?

Kanzenshuu provides the back history, context, and facts surrounding Super Saiyan 4's design by Katsuyoshi Nakatsuru (not Akira Toriyama!)

The inspiration behind Super Saiyan 4's design

Dragon Ball Xenoverse Adds Vegito And Super Saiyan 4 Goku - Siliconera

A Guide to Super Saiyan Green

What if Goku went Super Saiyan 4 to fight Jiren? - Quora

Rumor Guide - Kanzenshuu

Super Saiyan 10: Dragon Ball Z's Fiercest Form (and Why It'll NEVER Exist), Explained

Will there be a Dragon Ball Super season 2? Everything we know

Goku's New Super Saiyan Form Officially Confirmed

Dragon Ball: The Most Epic Episodes Where Goku Goes Super Saiyan

Vegeta

Manga Guide, Dragon Ball Super

Dragon Ball Reveals New Super Saiyan 4 Form

Goku and Vegeta getting wrecked, by Maniaxoi. : r/dbz