@article{GDZPPN001255282,
title = {The local theory of semigroups in nilpotent Lie groups.},
journal = {Semigroup forum},
volume = {23},
year = {1981},
pages = {343-358},
zbl = {0531.22002},
url = {http://dml.mathdoc.fr/item/GDZPPN001255282}
}
Hofmann, K.H.; Lawson, J.D. The local theory of semigroups in nilpotent Lie groups.. Semigroup forum, Tome 23 (1981) pp. 343-358. http://gdmltest.u-ga.fr/item/GDZPPN001255282/