Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
nhung cong » dung cong, thong cong, hang cong
hanh tang » hanh trang, anh tang, hanh mang
cong tac » cong ty
tac tren » rac tren, tai tren, tap tren
tren cau » tren ca, tren cay, tren tau
tang va » trang va, tang van, thang va

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 sach) or (chiet tach)) - hanh tang va nhung cong tac tren cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (chiet tach)) - hanh tang va nhung cong tac tren cau.
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) or (chiet tach)) - hanh tang va nhung cong tac tren cau*.