Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sach » chinh sach, chieu sang, chieu xanh
van dung » van dong, xay dung, tin dung
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan cau » toan cao, toan ban, toan tap
va dung » va duong, vat dung, va ung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sach) or (chiet tach)) - thanh trung ((va dung) OR (van dung)) cong bai toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (chiet tach)) - thanh trung ((va dung) OR (van dung)) cong bai toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sach) or (chiet tach)) - thanh trung ((va dung) OR (van dung)) cong bai toan cau".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (chiet tach)) - thanh trung ((va dung) OR (van dung)) cong bai toan cau*.