Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, ho chieu
hoc thieu » toc thieu, hoc hien
tranh vat » trinh vat, tranh va, tranh van
hang cong » dang cong, hang nong, bang cong
vat hang » van hang, dat hang, va hang
cong tan » cong tac, cong san, cong thanh
ban cau » bang cau, ban can, ban dau
van cau » van dau, van hau, van chat

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) or (hoc thieu)) sach - canh tranh vat hang cong tan ((ban cau) or (van cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (hoc thieu)) sach - canh tranh vat hang cong tan ((ban cau) OR (van cau)).
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (hoc thieu)) sach - canh tranh vat hang cong tan ((ban cau) or (van cau))*.