Borland (1998) explores the behaviour of a non-linear Fokker-Planck equation:

An equation is then derived
(Langevin equation) for the actual trajectories of the system, which are a function of *f.*

Borland L. 1998. Microscopic
dynamics of the nonlinear Fokker-Planck equation: A phenomenological
model. *Phys. Rev. E* 57, 6634-442