@article{AIHPC_2004__21_5_543_0,
     author = {Busca, J\'er\^ome and Sirakov, Boyan},
     title = {Harnack type estimates for nonlinear elliptic systems and applications},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {543--590},
     publisher = {Elsevier},
     volume = {21},
     number = {5},
     year = {2004},
     doi = {10.1016/j.anihpc.2003.06.001},
     mrnumber = {2086750},
     zbl = {02116180},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.anihpc.2003.06.001/}
}