@article{MM2_1980__33_154739,
     author = {Gu Chaohao},
     title = {On the {Initial-Boundary} {Value} {Problem} for {Harmonic} {Maps} from the {2-Dimensional} {Minkowski} {Space.}},
     journal = {Manuscripta mathematica},
     pages = {51--58},
     publisher = {mathdoc},
     volume = {33},
     year = {1980},
     zbl = {0447.53038},
     url = {http://geodesic.mathdoc.fr/item/MM2_1980__33_154739/}
}