@Misc{ 
  CupLeoMas15,
  author = { Cupini, Giovanni and Leonetti, Francesco and Mascolo, Elvira },
  title = { Existence of weak solutions for elliptic systems with $p,q$-growth },
  journal = { Ann. Acad. Sci. Fenn. Math. },
  year = { 2015 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/2594/ },
  note = { cvgmt preprint}
}