Perhaps you should try some spelling variations:
tthanh trung » thanh tung, thanh trang, hanh trang
thanh trung » thanh tung
trong doan » trong doanh, trong dan, trong hoan
hoc nhiet » hoc nghien, hoc hien, hoc viet
hoc thiet » hoc thieu, hoc thuyet, hoc hien
cap dung » ap dung, cao dung, chan dung
doan van » doan va, hoang van, luan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc nhiet) or (hoc thiet)) tach - ((thanh trung) or (tthanh trung)) cap dung trong doan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc nhiet) OR (hoc thiet)) tach - ((thanh trung) OR (tthanh trung)) cap dung trong doan van ban.
• Adding a wildcard symbol may retrieve word variants: ((hoc nhiet) or (hoc thiet)) tach - ((thanh trung) or (tthanh trung)) cap dung trong doan van ban*.