中国科学院数学与系统科学研究院期刊网
AMS
The Monotone Iterative Technique and Periodic Boundary Value Problem for First Order Impulsive Functional Differential Equations
HE Zhi Min, GE Wei Gao
Acta Mathematica Sinica . 2002, (2): 253 -262 .  DOI: 10.1007/s101140200155