Perhaps you should try some spelling variations:
nhung chong » nhung cong, nhung phong, nhung phuong
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
trung cap » truong cao, trung tam
chong bai » cuong bai, thong bai, chong lai
trung va » truong va, trang va, trung ha
bai toan » bai tap
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu sach - thanh ((trung va) or (trung cap)) nhung chong bai toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - thanh ((trung va) OR (trung cap)) nhung chong bai toan cao.
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - thanh ((trung va) or (trung cap)) nhung chong bai toan cao*.