High-quality mods typically use 48kHz/24-bit samples to avoid artifacting when the game engine shifts the pitch up or down. Getting Started
If you're writing about this or starting a project, focus on these technical pillars: ETS2 Create sound mods
You no longer just swap files. You create a .bank file that contains the logic for how sounds pitch-shift and cross-fade based on game telemetry. This is the official technical manual
This is the official technical manual. It explains the project structure, how to use the SCS FMOD template, and how the game engine communicates with sound events. These are the closest things to "peer-reviewed" papers
Experienced modders like Kriechbaum or Drive Safely often post technical breakdowns on the SCS Forums. These are the closest things to "peer-reviewed" papers in the modding community, detailing how to record high-fidelity engine sounds and loop them without seams. Key Concepts for Sound Modding