Second-order periodic problem with φ-Laplacian and impulses

Existence principles for the BVP(φ(u′(t)))′=f(t,u(t),u′(t))a.e. on[0,T],u(ti+)=Ji(u(ti)),u′(ti+)=Mi(u′(ti)),i=1,2,…,m,u(0)=u(T),u′(0)=u′(T)are presented. They are based on the method of lower/upper functions which need not be well-ordered.