Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » thong cong, hang cong, nhung don
trinh phan » trinh han, trinh quan, thanh phan
hieu lang » chieu sang, nhieu tang, hieu van
hanh sinh » hanh tinh, hanh dinh, hinh sinh
dung cong » dung trong
phan dau » phan tu, hang dau
sinh va » sinh vat, tinh va, dinh van

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 va ((nhung cong) OR (dung cong)) trinh phan dau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) OR (hieu quang)) - hanh sinh va ((nhung cong) OR (dung cong)) trinh phan dau".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) OR (hieu quang)) - hanh sinh va ((nhung cong) OR (dung cong)) trinh phan dau*.