Hj. Li, OSCILLATION OF SOLUTIONS OF 2ND-ORDER NEUTRAL DELAY-DIFFERENTIAL EQUATIONS WITH INTEGRABLE COEFFICIENTS, Mathematical and computer modelling, 25(3), 1997, pp. 69-79
Some necessary conditions are established for the nonoscillation of so
lutions of the second-order neutral delay differential equation [a(t)(
x(t)+p(t)x(t - tau))']' + q(t)f(x(t - sigma)) = 0. Using these results
, we obtain some oscillation criteria for the above equation.