Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
trinh cua » trinh luat, trinh quan, trinh luan
trinh han » trinh quan
doi hieu » doi chieu, doc hieu, doi hien
tinh cua » sinh cua, tinh chat, tranh cua
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cao » toan cao, thai cao, than cap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hanh ((((trinh cua) OR (trinh han))) OR (tinh cua)) nhung cong dan than cao~.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh ((((trinh cua) or (trinh han))) or (tinh cua)) nhung cong dan than cao*.