Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
thong cong » trong cong, tong cong, thong thong
hoc thieu » toc thieu, hoc hien
dai thong » dai tuong, dai hong, dai thang
cong dai » cong dan, cong hai, cong da
dan toan » dan than, manh toan, xuan toan
van toan » van tuan, van tan, van thanh

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 dai thong cong ((dan toan) or (van toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - thanh cong dai thong cong ((dan toan) OR (van toan)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - thanh cong dai thong cong ((dan toan) or (van toan)) cao*.