S1MD Green Hill Zone tilesets in S1MDMS style by HidroGeniuns on DeviantArt

Green Hill Zone Sprites Mania by Alex13Art on DeviantArt

User blog:SalaComMander/SalaComMander's first sprite comic, Sonic Wiki Zone

Pixel Joint Forum: Sonic 1 Title separate BG sprites?

Sonic 1 green hill zone sprites

Knuckles' Chaotix, knuckles Chaotix, Green Hill Zone, tilebased Video Game, Sonic Mania, Sonic the Hedgehog 2, cyan, Sprites, Tails, sprite

Green Hills Zone Sprites by Alex13Art on DeviantArt

Chronicles' GHZ - Stage, Models, etc WIP thread, Page 3

green hill in simple sonic worlds by chucknick - Game Jolt

Sonic The Hedgeblog — In early 'Sonic 1′ screenshots the Green Hill Zone

The VG Resource - Dolphman's sprite library of customs & edits