Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
sinh sach » chinh sach, sinh san, sang sach
tuong va » truong va, thuong va, luong va
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan cao » toan ban, toan tap
tung va » trung va, dung va, vung va

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

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