Perhaps you should try some spelling variations:
trong quang » truong quang, thong quang, trong quan
tcanh tranh » thanh thanh, can tranh, lanh tranh
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
khoa trong » hoa trong, khoa trung, khoang trong
quang van » quang ban, quan van, quang uan
cua khoa » chua khoa, sua khoa, qua khoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((chieu sang) OR (chieu sach)) - ((canh tranh) or (tcanh tranh)) cua khoa trong quang van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sang) OR (chieu sach)) - ((canh tranh) OR (tcanh tranh)) cua khoa trong quang van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu sang) OR (chieu sach)) - ((canh tranh) or (tcanh tranh)) cua khoa trong quang van ban".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sang) OR (chieu sach)) - ((canh tranh) or (tcanh tranh)) cua khoa trong quang van ban*.