Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
hanh trang » thanh trung, canh tranh, hanh trinh
hanh tang » anh tang, hanh mang, hanh tung
dang cong » dung cong
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
va dang » van dang, va nang, va lang

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

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