@article{JCA_2006_13_3_JCA_2006_13_3_a19,
     author = {Y. S. Ledyaev and J. S. Treiman and Q. J. Zhu},
     title = {Helly's {Intersection} {Theorem} on {Manifolds} of {Nonpositive} {Curvature}},
     journal = {Journal of convex analysis},
     pages = {785--798},
     publisher = {mathdoc},
     volume = {13},
     number = {3},
     year = {2006},
     url = {http://geodesic.mathdoc.fr/item/JCA_2006_13_3_JCA_2006_13_3_a19/}
}