How to install CSS Content For Garrys Mod (QUICK!) READ DESC - YouTube
Garry's Mod TTT - How to get CSS textures for free - YouTube
GmodContent.com - Download CSS, HL2, L4D Garry's Mod Content Textures
Garry's Mod - Download - CHIP
GMOD] Day Of Defeat + Counter-Strike: Source by Scout-Artist on DeviantArt
GitHub - ITS-NIGHTOWL/CSSource-Texture-Installer: A utility designed to help make installing CSSource textures into Garrys Mod safe while also doing it the legal method by utilizing steamcmd.