Perhaps you should try some spelling variations:
chieu xanh » chieu sang, chieu tinh, hieu manh
chieu sach » chinh sach, chiet tach, chieu sang
hanh tang » hanh trang, anh tang, hanh mang
dung cong » dung trong
cong tan » cong tac, cong san, cong thanh
tang su » tang suc, trang su, dang su
tan van » tran van, tang van, luan van

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 xanh) or (chieu sach)) - hanh tang su dung cong tan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu xanh) OR (chieu sach)) - hanh tang su dung cong tan van ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu xanh) or (chieu sach)) - hanh tang su dung cong tan van ban*.