@article{DAN_1982_265_3_a5,
     author = {G. I. Olshanskii},
     title = {Convex cones in symmetric {Lie} algebras, {Lie} semigroups and invariant causal (order) structures on {pseudo-Riemannian} symmetric spaces},
     journal = {Doklady Akademii Nauk},
     pages = {537--541},
     year = {1982},
     volume = {265},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1982_265_3_a5/}
}