@article{EJDE_1997__1997__a6,
     author = {Adams,  D.R. and Nussenzveig Lopes,  H.J.},
     title = {Nonlinear weakly elliptic \(2\times 2\) systems of variational inequalities with unilateral obstacle constraints},
     journal = {Electronic journal of differential equations},
     year = {1997},
     volume = {1997},
     zbl = {0890.35056},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_1997__1997__a6/}
}