Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
hanh sinh » hanh tinh, hanh dinh, hinh sinh
dung cong » dung trong
sinh cua » manh cua, dinh cuu, sinh va
cua dung » cua dang, cua dong, qua dung
phan dau » phan tu, hang dau
van dau » van dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) or (hieu quang)) - hanh sinh cua dung cong trinh ((van dau) OR (phan dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu quang)) - hanh sinh cua dung cong trinh ((van dau) OR (phan dau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) or (hieu quang)) - hanh sinh cua dung cong trinh ((van dau) OR (phan dau))".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (hieu quang)) - hanh sinh cua dung cong trinh ((van dau) OR (phan dau))*.