Lyapunov functions.

Lyapunov functionals and stability of stochastic difference equations Shaĭkhet, L. E. 2011 Networked and distributed predictive control Panagiotis D. Christofides, Jinfeng Liu, David Muñoz de la Peña 2011 Practical stability of nonlinear systems Lakshmikantham, V. 1990