Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
chieu sang » chieu sach, chieu xanh, hieu lang
trinh quan » tinh quang, trinh luat, trinh han
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
hang cong » dang cong, hang nong, thanh cong
bang cong » dang cong, bang song, dung cong
quan dau » quan cau, qua dau, quan dac

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 quang) or (chieu sang)) - hanh tinh chat ((hang cong) OR (bang cong)) trinh quan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu quang) OR (chieu sang)) - hanh tinh chat ((hang cong) OR (bang cong)) trinh quan dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quang) or (chieu sang)) - hanh tinh chat ((hang cong) OR (bang cong)) trinh quan dau".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quang) or (chieu sang)) - hanh tinh chat ((hang cong) OR (bang cong)) trinh quan dau*.