Perhaps you should try some spelling variations:
theo chieu » ho chieu, theo chu, thi chieu
canh trinh » canh tranh, hanh trinh, canh tinh
hang cong » dang cong, hang nong, bang cong
than phan » thanh phan, toan phan, thanh pham
trinh va » trinh van, trinh vat, trinh ve
tan phan » toan phan, van phan, tai phan
va hang » van hang, va nang, va lang

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) or (theo tieu)) sach - canh trinh va hang cong ((tan phan) OR (than phan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (theo tieu)) sach - canh trinh va hang cong ((tan phan) OR (than phan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) or (theo tieu)) sach - canh trinh va hang cong ((tan phan) OR (than phan)) cau".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) or (theo tieu)) sach - canh trinh va hang cong ((tan phan) OR (than phan)) cau*.