@article{JRAM_1975__276_151597,
     author = {James Conlan and Robert P. Gilbert},
     title = {Non-linear initial data for second and higher order semi-linear elliptic equations.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {1--14},
     publisher = {mathdoc},
     volume = {276},
     year = {1975},
     zbl = {0311.35045},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1975__276_151597/}
}