Perhaps you should try some spelling variations:
tieu sach » chieu sach, dien sach, te sach
anh nang » ganh nang, anh bang, anh dang
nang duc » nang luc, nang doc, nang du
duc tung » duc trung, duc hung, duc dung
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
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 tieu sach - anh nang duc tung ((cong tan) or (cong tac)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo tieu sach - anh nang duc tung ((cong tan) OR (cong tac)) toan cau.
• Adding a wildcard symbol may retrieve word variants: theo tieu sach - anh nang duc tung ((cong tan) or (cong tac)) toan cau*.