File:Sonic 2 Stage Select.png - Wikibooks, open books for an open world

Sonic The Hedgehog 2 cheat for Mega Drive/Genesis - Level Select (with save state for emulators)

Sonic the Hedgehog 2 (16-bit)/Hidden content - Sonic Retro

Did You Know Gaming? — Sonic The Hedgehog 2 (Genesis/Mega Drive). Cheat

Every Cheat Code in Sonic Origins

Sonic the Hedgehog 2 (Genesis) - Super Sonic Cheat

Sonic the Hedgehog 2 Mega Drive/Genesis System – What's it all about?, Reviews#

Sonic the Hedgehog 2 (Mega Drive) - The Cutting Room Floor

Sonic Origins cheats, level select, debug mode, Hidden Palace Zone

Hacking Sonic The Hedgehog 2 (GEN) – Game Genie Hijinx!, Video Game Hacking#

Sonic Origins cheat codes for level select, debug mode and Super Sonic