@article{EJDE_2012__2012__a28,
     author = {Afrouzi, Ghasem A. and Mirzapour, Maryam and Zhang, Qihu},
     title = {Simplicity and stability of the first eigenvalue of a $(p;q)$ {Laplacian} system},
     journal = {Electronic Journal of Differential Equations},
     publisher = {mathdoc},
     volume = {2012},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2012__2012__a28/}
}