Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
cong luong » cong thuong, nang luong, cong dong
hieu lang » chieu sang, hieu quang, nhieu tang
hanh tang » hanh trang, anh tang, hanh mang
cong lang » cong vang, cong quang, cong ngang
tang cua » mang cua, hang cua, tang luan
toan cau » toan cao, toan ban, toan tap

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 sach) or (hieu lang)) - hanh tang cua ban ((cong lang) or (cong luong)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (hieu lang)) - hanh tang cua ban ((cong lang) OR (cong luong)) toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (hieu lang)) - hanh tang cua ban ((cong lang) or (cong luong)) toan cau*.