Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, nhung don
hieu lang » chieu sang, hieu quang, nhieu tang
hanh mang » nhanh mang, hanh trang, nhanh lang
hang cong » dang cong, hang nong, bang cong
doi hieu » doi chieu, doc hieu, doi hien
mang cua » manh cua, dung cua, ban cua
phan cau » phan dau, phan cac, phan lap

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 mang cua ((nhung cong) OR (hang cong)) dan ((phan cau) OR (phan tu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - hanh mang cua ((nhung cong) OR (hang cong)) dan ((phan cau) or (phan tu))~".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh mang cua ((nhung cong) OR (hang cong)) dan ((phan cau) or (phan tu))*.