@article{GDZPPN002224763, title = {Sine - Laplace Equation, Sinh-Laplace Equation and Harmonic Maps.}, journal = {Manuscripta mathematica}, volume = {39}, year = {1982}, pages = {205-216}, zbl = {0511.35061}, url = {http://dml.mathdoc.fr/item/GDZPPN002224763} }
Hesheng, Hu. Sine - Laplace Equation, Sinh-Laplace Equation and Harmonic Maps.. Manuscripta mathematica, Tome 39 (1982) pp. 205-216. http://gdmltest.u-ga.fr/item/GDZPPN002224763/