@article{Liang2023, 
author = {Zaitao Liang and Xiuqiang Zhang and Shengjun Li and Ziqing Zhou},
title = {Periodic solutions of a class of indefinite singular differential equations},
year = {2023},
journal = {Electronic Research Archive},
volume = {31},
number = {4},
pages = {2139-2148},
keywords = {indefinite singular equations, periodic solutions, fixed point theorem},
url = {https://www.sciopen.com/article/10.3934/era.2023110},
doi = {10.3934/era.2023110},
abstract = {In this article, some sufficient conditions for the existence of positive periodic solutions of a more general indefinite singular differential equation are established. The results are applicable to strong singularities as well as weak singularities. Some results in literature are generalized.}
}