Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hanh trang » thanh trung, canh tranh, hanh trinh
chua dang » chua dong, chua nang, chua xang
hieu van » hieu va, thien van, lieu va
cua dang » cua cong, cua ban
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
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: theo ((chieu sach) or (hieu van)) - hanh trang ((chua dang) or (cua dang)) cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (hieu van)) - hanh trang ((chua dang) OR (cua dang)) cong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) or (hieu van)) - hanh trang ((chua dang) or (cua dang)) cong tac toan cau*.