Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
viet tach » viet sach, viet tech, viet thanh
trinh vat » trinh van, trinh luat, sinh vat
doi viet » dai viet, hoi viet, oi viet
tranh va » tranh van, trang va, trinh va
cong tan » cong tac, cong san, cong thanh
tan phan » toan phan, than phan, van phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi viet tach - canh ((tranh va) or (trinh vat)) nhung cong tan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi viet tach - canh ((tranh va) OR (trinh vat)) nhung cong tan phan tu*.