Oscillation theorems for the damped elliptic differential equation of second order
are obtained. The results are extensions of averaging techniques due to Coles and Kamenev, and include earlier known results in literature.
"Oscillation theorems for damped elliptic differential equations of second order." Hiroshima Math. J. 38 (1) 1 - 17, March 2008. https://doi.org/10.32917/hmj/1207580341