Perhaps you should try some spelling variations:
thieu hach » thien hach, chieu sach, hieu cach
hoc thieu » toc thieu, hoc hien
trung cua » truong cua, trung tuan, trung cap
dung cong » dung trong
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
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 thieu hach - thanh ((trung cua) or (truong dai)) dung cong van toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu hach - thanh ((trung cua) OR (truong dai)) dung cong van toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc thieu hach - thanh ((trung cua) or (truong dai)) dung cong van toan cao*.