@article{1102983771, author = {Headley, V. B. and Swanson, C. A.}, title = {Oscillation criteria for elliptic equations.}, journal = {Pacific J. Math.}, volume = {27}, number = {3}, year = {1968}, pages = { 501-506}, language = {en}, url = {http://dml.mathdoc.fr/item/1102983771} }
Headley, V. B.; Swanson, C. A. Oscillation criteria for elliptic equations.. Pacific J. Math., Tome 27 (1968) no. 3, pp. 501-506. http://gdmltest.u-ga.fr/item/1102983771/