The periodic problem for the second order integro-differential equations with distributed deviation
We study the question of the unique solvability of the periodic type problem for the second order linear integro-differential equation with distributed argument deviation and on the basis of the obtained results by the a priori boundedness principle we prove the new results on the solvability of periodic type problem for the second order nonlinear functional differential equations, which are close to the linear integro-differential equations. The proved results are optimal in some sense.