Guerfi A, Ardjouni A. Existence of periodic or nonnegative periodic solutions for totally nonlinear neutral differential equations with infinite delay. Proyecciones (Antofagasta, On line) [Internet]. 2022Oct.28 [cited 2024Apr.26];41(6):1297-319. Available from: https://www.revistaproyecciones.cl/index.php/proyecciones/article/view/5208