@article{1102986021, author = {Cootz, Thomas A.}, title = {A maximum principle and geometric properties of level sets.}, journal = {Pacific J. Math.}, volume = {27}, number = {3}, year = {1968}, pages = { 39-46}, language = {en}, url = {http://dml.mathdoc.fr/item/1102986021} }
Cootz, Thomas A. A maximum principle and geometric properties of level sets.. Pacific J. Math., Tome 27 (1968) no. 3, pp. 39-46. http://gdmltest.u-ga.fr/item/1102986021/