中国科学院数学与系统科学研究院期刊网
Existence and Multiplicity of Positive Periodic Solutions for a Class of Functional Differential Equations
JING Lan, MO Yichun
Acta Mathematicae Applicatae Sinica . 2014, (2): 234 -246 .  DOI: 10.12387/C2014022