Perhaps you should try some spelling variations:
thieu sach » thien hach, hieu cach, theo sach
chieu sach » chinh sach, chiet tach, chieu sang
dung cong » dung trong
cong hach » cong sach, cong thanh, cong khanh
hach toan » thanh toan, manh toan
anh hang » anh hoang, anh hung, anh dang
anh bang » anh hoang, anh quang, tinh bang
toan ban » van ban
ca dung » cao dung, cap dung, cu 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) or (chieu sach)) - ((anh hang) OR (anh bang)) ca dung cong hach toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (chieu sach)) - ((anh hang) OR (anh bang)) ca dung cong hach toan ban*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (chieu sach)) - ((anh hang) OR (anh bang)) ca dung cong hach toan ban*".