中国科学院数学与系统科学研究院期刊网
Small-divisor Equation of Higher Order with Large Variable Coefficient and Application to the Coupled KdV Equation
Mei Na GAO, Jing ZHANG
Acta Mathematica Sinica . 2011, (10): 2005 -2032 .  DOI: 10.1007/s10114-011-0064-1