Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
chi hanh » chi nhanh, chi thanh, thi hanh
tranh va » tranh van, trang va, thanh va
trinh va » trinh van, trinh vat, trinh ve
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan ban » van ban
chi van » thi van, chu van

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((chi hanh) or (chi van)) - canh ((tranh va) or (trinh va)) nhung cong bai toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chi hanh) OR (chi van)) - canh ((tranh va) OR (trinh va)) nhung cong bai toan ban.
• Adding a wildcard symbol may retrieve word variants: doi ((chi hanh) or (chi van)) - canh ((tranh va) or (trinh va)) nhung cong bai toan ban*.