@article{JOLT_1994_4_1_a1,
     author = {J. D. Lawson},
     title = { Maximal {Ol'shanskii} {Semigroups}},
     journal = {Journal of Lie Theory},
     pages = {17--30},
     year = {1994},
     volume = {4},
     number = {1},
     zbl = {0824.22012},
     url = {http://geodesic.mathdoc.fr/item/JOLT_1994_4_1_a1/}
}