@article{AIHPC_1992__9_4_339_0,
     author = {Tso, Kaising},
     title = {Nonlinear symmetric positive systems},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {339--366},
     publisher = {Gauthier-Villars},
     volume = {9},
     number = {4},
     year = {1992},
     mrnumber = {1186682},
     zbl = {0776.35037},
     language = {en},
     url = {http://archive.numdam.org/item/AIHPC_1992__9_4_339_0/}
}