Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
trang va » tran van, hang va
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
bang va » hang va, ban va, dang van

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo hieu lang - hong ((bang va) OR (trang va)) nhung cong tac toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo hieu lang - hong ((bang va) OR (trang va)) nhung cong tac toan cau".
• Adding a wildcard symbol may retrieve word variants: theo hieu lang - hong ((bang va) OR (trang va)) nhung cong tac toan cau*.