@article{MM2_1992__74_2_155683,
     author = {Atsushi Tachikawa},
     title = {Harmonic maps from a {Riemannian} manifold with a pole into an {Hadamard} manifold with negative sectional curvatures.},
     journal = {Manuscripta mathematica},
     pages = {69--82},
     publisher = {mathdoc},
     volume = {74},
     number = {2},
     year = {1992},
     zbl = {0753.58007},
     url = {http://geodesic.mathdoc.fr/item/MM2_1992__74_2_155683/}
}