Perhaps you should try some spelling variations:
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
vi trung » va trung, viet trung, vien trung
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan tap » toan ban
vi dung » va dung, vi ung, vi dong

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 - canh tranh ((vi dung) or (vi trung)) cong tan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hieu lang - canh tranh ((vi dung) OR (vi trung)) cong tan toan tap.
• Adding a wildcard symbol may retrieve word variants: theo hieu lang - canh tranh ((vi dung) or (vi trung)) cong tan toan tap*.