@article{SF_1996__52_3_135460,
     author = {G.B. Shi and G.P. Wang},
     title = {Z-mappings and a classification theorem.},
     journal = {Semigroup forum},
     pages = {349--356},
     publisher = {mathdoc},
     volume = {52},
     number = {3},
     year = {1996},
     zbl = {0847.06001},
     url = {http://geodesic.mathdoc.fr/item/SF_1996__52_3_135460/}
}