Perhaps you should try some spelling variations:
thieu hach » thien hach, chieu sach, hieu cach
nhung cong » thong cong, hang cong, nhung don
hoc thieu » toc thieu, hoc hien
trung cua » truong cua, trung tuan, trung cap
dung cong » dung trong
van tan » van tuan, van ban, van tai
tan cao » toan cao, tao cao, tay cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu hach - thanh ((trung cua) or (truong dai)) ((nhung cong) OR (dung cong)) van tan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu hach - thanh ((trung cua) OR (truong dai)) ((nhung cong) OR (dung cong)) van tan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu hach - thanh ((trung cua) or (truong dai)) ((nhung cong) OR (dung cong)) van tan cao".
• Adding a wildcard symbol may retrieve word variants: hoc thieu hach - thanh ((trung cua) or (truong dai)) ((nhung cong) OR (dung cong)) van tan cao*.