For citations:

Chiu K., Cordova-Lepe F. Some conditions for the existence of 4-periodic solutions in non-homogeneous differential equations involving piecewise alternately advanced and retarded arguments. Nanosystems: Physics, Chemistry, Mathematics. 2024;15(6):749-754. https://doi.org/10.17586/2220-8054-2024-15-6-749-754