Perhaps you should try some spelling variations:
hanh cong » thanh cong, hanh dong, nhanh chong
hang cong » dang cong, hang nong, bang cong
dung cong » dung trong
theo chu » theo chieu, cho chu, chao chu
chu sach » cau sach, thu sach, chieu sach
cua dung » cua dang, cua dong, qua dung
van toan » van tuan, van tan, van thanh
dan than » dan chan, ban than, van than

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chu sach - ((hanh cong) OR (hang cong)) cua dung cong ((van toan) or (dan than)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chu sach - ((hanh cong) OR (hang cong)) cua dung cong ((van toan) OR (dan than)) tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chu sach - ((hanh cong) OR (hang cong)) cua dung cong ((van toan) or (dan than)) tap".
• Adding a wildcard symbol may retrieve word variants: theo chu sach - ((hanh cong) OR (hang cong)) cua dung cong ((van toan) or (dan than)) tap*.