If you are specifically looking for a .rar file of these papers, be aware that many of these are copyrighted academic texts or proprietary industrial data. You can find high-level summaries and purchase options for Cossalter's work on major academic publishing sites. Are you trying to for a specific bike, or TrackDayR – The Unleashed Sim

: The game integrates various validated industrial formulas to replicate accurate motorcycle movements rather than using simplified "arcade" physics.

If you are looking for an academic foundation for (TDR), the developers have explicitly stated that the game's physics are based on the work of Vittorio Cossalter , specifically his seminal book Motorcycle Dynamics .

This "solid paper" you’re likely after isn't just one document but a collection of industrial and academic research used to build the sim's realistic tire and bike behavior:

: The developers highlight this as a primary source for their physics model.