Perhaps you should try some spelling variations:
thuyet tach » thuyet hach, thuyet xac, thuyet cac
thuyet mach » thuyet xac, thuyet cac, thuyet anh
hanh trinh » canh tranh, hanh chinh
trong vang » trong van, trong dang, trong tang
trinh cua » tinh cua, trinh luat, trinh quan
vang toan » van toan, dang toan, quang toan
cua dung » cua dang, cua dong, qua dung
toan cau » toan cao, toan ban, toan tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thuyet tach) OR (thuyet mach)) - hanh trinh cua dung trong vang toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thuyet tach) OR (thuyet mach)) - hanh trinh cua dung trong vang toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thuyet tach) OR (thuyet mach)) - hanh trinh cua dung trong vang toan cau*.