The Dreamcast Junkyard: A Quick Look At Sonic Adventure 2's Green Hill Zone

Knuckles in Sonic 2 Green Hill Zone by Hivebrain V0.2 (S2 Hack) : Free Download, Borrow, and Streaming : Internet Archive

Green Hill Zone - Wikipedia

Green Hill (Sonic Adventure 2) - Sonic Retro

Sonic Mania Gameplay: Green Hill Zone Act 2 - PAX East - IGN

Steam Workshop::Green Hill Zone: Act 2 [Caverns]

Sonic the Hedgehog 2 (pre-beta)/Comparisons/Neo Green Hill Zone - Sonic Retro

Worms Map Database - Maps - Green Hill Zone Act 2

The Spriters Resource - Full Sheet View - Sonic the Hedgehog (Prototype) - Green Hill Zone Act. 2

Hacks - Sonic 2 Early Prototype Green Hill Zone Fix

Sonic Advance - Neo Green Hill Zone Act 1 - Lead Sheets for Video Game Music