Which paper is the basis of slip-based tire friction model of Wheel Collider?

The documentation of WheelCollider says

Wheel collider is used to model
vehicle wheels. It simulates a spring
and damper suspension setup, and uses
a slip based tire friction model to
calculate wheel contact forces.

Can someone point me to the paper the implementation is based on? My guess, it’ll be the work of F. Gustafsson. But I’d like to identify which publication.

If you consider the documentation is incomplete, please submit a bug report and our developers will consider adding the missing information.