@article{TSG_1988-1989__7__33_0,
     author = {Ballmann, Werner},
     title = {On the {Dirichlet} problem at infinity for manifolds of non-positive curvature (r\'esum\'e)},
     journal = {S\'eminaire de th\'eorie spectrale et g\'eom\'etrie},
     pages = {33--34},
     publisher = {Institut Fourier},
     address = {Grenoble},
     volume = {7},
     year = {1988-1989},
     language = {en},
     url = {http://www.numdam.org/item/TSG_1988-1989__7__33_0/}
}