Shi, Jinlin On the stability of second-order linear differential equations with periodic coefficient. (Chinese. English summary) Zbl 0961.34040 Acta Math. Sci. (Chin. Ed.) 20, No. 1, 130-139 (2000). MSC: 34D20 34A30 PDFBibTeX XMLCite \textit{J. Shi}, Acta Math. Sci. (Chin. Ed.) 20, No. 1, 130--139 (2000; Zbl 0961.34040)
Shi, Jinlin On the characteristic exponent of two-dimensional linear differential equations with periodic coefficients. (Chinese. English summary) Zbl 0922.34043 Acta Math. Sci. (Chin. Ed.) 19, No. 1, 67-72 (1999). MSC: 34D08 34A30 PDFBibTeX XMLCite \textit{J. Shi}, Acta Math. Sci. (Chin. Ed.) 19, No. 1, 67--72 (1999; Zbl 0922.34043)