中国科学院数学与系统科学研究院期刊网
A SIRS EPIDEMIOLOGICAL MODEL WITH NONLINEAR INCIDENCE RATE AND DELAY
Zhi Xing HU, Hui WANG, Ke Ying GUAN
Acta Mathematicae Applicatae Sinica . 1999, (1): 10 -016 .  DOI: 10.12387/C1999014