Perhaps you should try some spelling variations:
thieu sach » chieu sach, hieu cach, theo sach
thien hach » thien thanh, hien hanh
manh trung » manh tung, thanh trung, manh hung
trung cua » truong cua, trung tuan, trung cap
dung cong » dung trong
cua dung » cua dang, cua dong, qua dung
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) OR (thien hach)) - manh trung cua dung cong ((dan toan) or (van toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (thien hach)) - manh trung cua dung cong ((dan toan) OR (van toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) OR (thien hach)) - manh trung cua dung cong ((dan toan) or (van toan)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) OR (thien hach)) - manh trung cua dung cong ((dan toan) or (van toan)) cau*.