@article{JLT_1992_2_1_a4,
     author = {K. H. Hofmann},
     title = {Compact {Elements} in {Solvable} {Real} {Lie} {Algebras}},
     journal = {Journal of Lie theory},
     pages = {041--056},
     publisher = {mathdoc},
     volume = {2},
     number = {1},
     year = {1992},
     url = {http://geodesic.mathdoc.fr/item/JLT_1992_2_1_a4/}
}