@article{JLT_1992_2_2_a8,
     author = {A. Levichev and V. Levicheva},
     title = {Distinguishability {Conditions} and the {Future} {Semigroup}},
     journal = {Journal of Lie theory},
     pages = {205--212},
     publisher = {mathdoc},
     volume = {2},
     number = {2},
     year = {1992},
     url = {http://geodesic.mathdoc.fr/item/JLT_1992_2_2_a8/}
}