Variational Method to Nonlinear Fourth-Order Impulsive Partial Differential Equations
By using the critical point theory of variational method and Lax-Milgram theorem, we obtain the new results for the solution existence of the fourth-order impulsive partial differential equations with periodic boundary value problems.
H. C. Li and Y. L. Zhang, "Variational Method to Nonlinear Fourth-Order Impulsive Partial Differential Equations", Advanced Materials Research, Vols. 261-263, pp. 878-882, 2011