Perhaps you should try some spelling variations:
chinh quang » tinh quang, nhanh quang, dinh quang
chieu sang » chieu sach, chieu xanh, hieu lang
chieu tinh » trieu tinh, lieu tinh, chau tinh
quang dung » quang trung, ung dung, cuong dung
dung cuong » dung cong, dung luong, dang cuong
tap toan » tap quan, bai toan
tap doan » tap quan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sang) or (chieu tinh)) - hanh chinh quang dung cuong ((tap toan) OR (tap doan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (chieu tinh)) - hanh chinh quang dung cuong ((tap toan) OR (tap doan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (chieu tinh)) - hanh chinh quang dung cuong ((tap toan) OR (tap doan)) cao".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (chieu tinh)) - hanh chinh quang dung cuong ((tap toan) OR (tap doan)) cao*.