Existence Results for Neutral and Second-Order Functional Differential Equations with Causal Operators in $L^p_{\mathrm{loc}}$ Spaces. Eur. J. Pure Appl. Math. [Internet]. 2026 Feb. 16 [cited 2026 Feb. 17];19(1):7151. Available from: https://www.ejpam.com/index.php/ejpam/article/view/7151