Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
cua thong » cua thuong, cua khong, cua tong
van manh » van minh, van anh, van hanh
cong tac » cong ty
toan cao » toan ban, toan tap
co sach » bo sach, cuon sach, hoc sach
doi co » doi bo, moi co, hoi co

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi co sach - ((van manh) or (van thanh)) cua thong ((cong san) or (cong tac)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi co sach - ((van manh) OR (van thanh)) cua thong ((cong san) OR (cong tac)) toan cao.
• Adding a wildcard symbol may retrieve word variants: doi co sach - ((van manh) or (van thanh)) cua thong ((cong san) or (cong tac)) toan cao*.