Comments on Bouda and Djama's "Quantum Newton's law"
  Discussion of the differences between the trajectory representation of Floyd and that of Bouda and Djama [Phys. Lett. A 285 (2001) 27, quant-ph/0103071] renders insight: while Floyd's trajectories are related to group velocities, Bouda and Djama's are not. Bouda and Djama's reasons for these differences are also addressed. 
Edward R. Floyd