Perhaps you should try some spelling variations:
thanh trung » thanh tung
hoc thiet » hoc thuyet, hoc hien, toc thieu
hoc thieu » toc thieu, hoc hien
trung ha » trung hoc, trung tam, trung cap
ha trong » hoa trong, hai trong, hat trong
cong dan » cong san, cong tan, huong dan
chan cao » chan cho, chay cao, toan cao
chat cao » chat co, chat cho, chat bao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc thiet) or (hoc thieu)) hach - thanh trung ha trong cong dan ((chan cao) or (chat cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thiet) OR (hoc thieu)) hach - thanh trung ha trong cong dan ((chan cao) OR (chat cao)).
• Adding a wildcard symbol may retrieve word variants: ((hoc thiet) or (hoc thieu)) hach - thanh trung ha trong cong dan ((chan cao) or (chat cao))*.