@article{JMPA_1843_1_8__265_0,
     author = {Liouville, J.},
     title = {Sur l'\'equation $\frac{d^2\varphi}{dx^2}+\frac{d^2\varphi}{dy^2}=\mathrm{o}$},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {265--267},
     publisher = {Gauthier-Villars},
     volume = {1e s{\'e}rie, 8},
     year = {1843},
     language = {fr},
     url = {http://www.numdam.org/item/JMPA_1843_1_8__265_0/}
}