@article{GDZPPN002443902, title = {Harmonic maps form surfaces to R-trees.}, journal = {Mathematische Zeitschrift}, volume = {220}, year = {1995}, pages = {577-594}, zbl = {0827.58011}, url = {http://dml.mathdoc.fr/item/GDZPPN002443902} }
Wolf, Michael. Harmonic maps form surfaces to R-trees.. Mathematische Zeitschrift, Tome 220 (1995) pp. 577-594. http://gdmltest.u-ga.fr/item/GDZPPN002443902/