中国科学院数学与系统科学研究院期刊网
Some Existence Principles for the Singular Second Order Differential Equation(Ф(x'))' + f(t, x) = 0
刘希玉
Acta Mathematica Sinica, Chinese Series . 1996, (3):  .  DOI: 10.12386/A1996sxxb0057