Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
canh trinh » canh tranh, hanh trinh, canh tinh
dung cong » dung trong
trinh va » trinh van, trinh vat, trinh ve
cong tan » cong tac, cong san, cong thanh
than cap » khan cap, thanh lap, thanh cac
toan cau » toan cao, toan ban, toan tap
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc thieu sach - canh trinh va dung cong tan ((than cap) or (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu sach - canh trinh va dung cong tan ((than cap) OR (toan cau)).
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - canh trinh va dung cong tan ((than cap) or (toan cau))*.