Perhaps you should try some spelling variations:
thieu sang » thieu khang, thieu quang, hieu lang
chieu sang » chieu sach, chieu xanh, hieu lang
hanh tranh » hanh trinh, hanh trang, lanh tranh
thong dan » thong van, tuong dan, thong den
dan thanh » dang thanh, danh thanh, ban thanh
thanh ban » thanh san, thanh van, thanh bac
va thong » va thuong, va phuong, he thong

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sang) or (chieu sang)) - ((hanh tranh) OR (canh tranh)) va thong thong dan thanh ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (chieu sang)) - ((hanh tranh) OR (canh tranh)) va thong thong dan thanh ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (chieu sang)) - ((hanh tranh) OR (canh tranh)) va thong thong dan thanh ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (chieu sang)) - ((hanh tranh) OR (canh tranh)) va thong thong dan thanh ban*.