Perhaps you should try some spelling variations:
hanh trung » thanh trung, hanh trang, manh trung
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
cua dang » cua cong
cong tac » cong ty
tac tran » tan tran, tac trai, tac tren
tran cau » tran chau, toan cau, ran cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) OR (hieu lang)) - hanh trung ((cua dang) or (cua ban)) cong tac tran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - hanh trung ((cua dang) OR (cua ban)) cong tac tran cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) OR (hieu lang)) - hanh trung ((cua dang) or (cua ban)) cong tac tran cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) OR (hieu lang)) - hanh trung ((cua dang) or (cua ban)) cong tac tran cau*.