中国科学院数学与系统科学研究院期刊网
AMS
Positive and Nontrivial Solutions for the Urysohn Integral Equation
Daniel FRANCO, Gennaro INFANTE, Donal O’REGAN
Acta Mathematica Sinica . 2006, (6): 1745 -1750 .  DOI: 10.1007/s10114-005-0782-3