Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
trung cua » truong cua, trung tuan, trung cap
doi hieu » doi chieu, doc hieu, doi hien
tang cua » mang cua, hang cua, tang luan
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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 ((tang cua) OR (trung cua)) nhung cong dan toan cau~.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh ((tang cua) or (trung cua)) nhung cong dan toan cau*.