File:London2012 Shadow.png - Sonic Retro

Due to the lack of a proper timeline in the Sonic Encyclo-Speed-ia, I decided to make my own. Second image contains my notes, reasonings, and conjectures. : r/SonicTheHedgehog

File:SASRT Shadow.png - Sonic Retro

Mario & Sonic at the London 2012 Olympic Games (Nintendo 3DS) - Super Mario Wiki, the Mario encyclopedia

Shadow the Hedgehog/Gallery, Sonic Wiki Zone

Amy Rose Sonic News Network+BreezeWiki

Sonic the Hedgehog (2013) - The Cutting Room Floor

Silver the Hedgehog - Sonic Retro

File:London2012 Mario.png - Sonic Retro

File:ASR Shadow.png - Sonic Retro

Sonic Party Video Games

Mario & Sonic at the Olympic Winter Games - Sonic Spin-offs - Sonic Stadium

Sonic The Hedgehog Metal Sonic / Characters - TV Tropes