Perhaps you should try some spelling variations:
doi chieu » doi chi, ho chieu, mot chieu
truong va » truong dai, truong cao, truong dao
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
trung va » trang va, trung ha, trung tam
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doc hieu)) xanh - thanh ((trung va) OR (truong va)) dung cong tan toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) or (doc hieu)) xanh - thanh ((trung va) OR (truong va)) dung cong tan toan cao~".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (doc hieu)) xanh - thanh ((trung va) OR (truong va)) dung cong tan toan cao*.