Quasilinear elliptic systems with convex-concave singular terms   $\Phi\!-\!Laplacian$ operator
  This paper deals with existence of positive solutions for a class of quasilinear elliptic systems involving the $\Phi$-Laplacian operator and convex-concave singular terms. Our approach is based on the generalized Galerkin Method along with perturbartion techniques and comparison arguments in the setting of Orlicz-Sobolev spaces 
Carlos Alberto Santos, Marcos L. Carvalho, Jose V. Goncalves
math.AP