Different points on a rolling wheel have different velocities due to the combination of rotation and translation, which is a fundamental principle of rigid-body kinematics requiring no citation.
The claim is a fundamental, defining property of rolling motion in classical mechanics (the vector sum of translational velocity and rotational velocity varies by radial distance and angle). None of the retrieved papers specifically target or test this basic physics truism as an empirical hypothesis; the physics is trivially true by definition and everyday observation, making it common knowledge.