Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
dung cong » dung trong
van thang » van thanh, van khang, van hang
van than » van thanh, van tuan, van phan
cong va » dong va, cong ha, cong tac
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: hoc thieu sach - thanh cong va dung cong ((van than) or (van thang)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - thanh cong va dung cong ((van than) OR (van thang)) cau.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - thanh cong va dung cong ((van than) or (van thang)) cau*.