On the Schrodinger-Poisson system with inde nite potential and
3-sublinear nonlinearit 
Shibo Liua,1, Sunra Mosconib,2,
aSchool of Mathematical Sciences, Xiamen University, Xiamen 361005, China
bDipartimento di Matematica e Informatica, Universita di Catania, Viale A. Doria 6, 95125 Catania, Italy