Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
chieu sang » chieu sach, chieu xanh, nhieu tang
thanh chau » thanh cha, thanh cham, thanh chu
hieu lang » hieu quang, nhieu tang, hieu van
tan thanh » tran thanh, tang thanh, toan thanh
cua dang » cua ban
cong tan » cong tac, cong san, cong thanh

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 lang) OR (chieu sang)) - hanh tranh ((cua dang) or (cua cong)) cong tan thanh chau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu lang) OR (chieu sang)) - hanh tranh ((cua dang) OR (cua cong)) cong tan thanh chau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu lang) OR (chieu sang)) - hanh tranh ((cua dang) or (cua cong)) cong tan thanh chau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu lang) OR (chieu sang)) - hanh tranh ((cua dang) or (cua cong)) cong tan thanh chau*.