The following publications are possibly variants of this publication:
- The existence of multiple positive periodic solutions for functional differential equationsWeihua Jiang. amc, 208(1):165-171, 2009. [doi]
- A new existence theory for single and multiple positive periodic solutions to volterra integro-differential equations with impulse effectsXiaoying Zhang, Daqing Jiang, Xiaoyue Li, Ke Wang. cma, 51(1):17-32, 2006. [doi]
- A new existence theory for positive periodic solutions to functional differential equations with impulse effectsXiaoyue Li, Xiaoying Zhang, Daqing Jiang. cma, 51(12):1761-1772, 2006. [doi]