共 16 条
[4]
Graef JR, 2006, DYNAM SYST APPL, V15, P97
[5]
Gupta C., 2001, ELECT J DIFFER EQU C, V7, P47
[7]
Gupta CP, 2004, PROCEEDINGS OF DYNAMIC SYSTEMS AND APPLICATIONS, VOL 4, P439
[9]
GUPTA CP, 2001, DYNAM SYSTEMS APPL, V3, P249