@article{GDZPPN001264893,
title = {Z-mappings and a classification theorem.},
journal = {Semigroup forum},
volume = {53},
year = {1996},
pages = {349-356},
zbl = {0847.06001},
url = {http://dml.mathdoc.fr/item/GDZPPN001264893}
}
Shi, G.B.; Wang, G.P. Z-mappings and a classification theorem.. Semigroup forum, Tome 53 (1996) pp. 349-356. http://gdmltest.u-ga.fr/item/GDZPPN001264893/