Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu xanh
chieu sang » chieu xanh, hieu lang, nhieu tang
cong quang » luong quang, thong quang, duong quang
hang cong » dang cong, hang nong, bang cong
quang tai » quang thai, quang tri, quan tai
mang va » mang vua, hang va, dang va
bang va » hang va, ban va, trang va
tai cao » thai cao, tao cao, tai sao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sach) or (chieu sang)) - hanh ((mang va) OR (bang va)) hang cong quang tai cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (chieu sang)) - hanh ((mang va) OR (bang va)) hang cong quang tai cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) or (chieu sang)) - hanh ((mang va) OR (bang va)) hang cong quang tai cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (chieu sang)) - hanh ((mang va) OR (bang va)) hang cong quang tai cao*.