Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
dung cong » dung trong
doc hieu » toc thieu, hoc hien
trung va » truong va, trang va, trung tam
trung ha » trung hoc, trung tam, trung cap
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
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: ((doc hieu) or (hoc thieu)) manh - thanh ((trung va) or (trung ha)) dung cong tan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (hoc thieu)) manh - thanh ((trung va) OR (trung ha)) dung cong tan toan cao.
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (hoc thieu)) manh - thanh ((trung va) or (trung ha)) dung cong tan toan cao*.