Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
canh manh » lanh manh, canh tranh, cach mang
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
hieu van » hieu va, thien van, lieu va
manh cua » doanh cua, ban cua
san toan » van toan, dan toan, manh toan
toan ban » van ban

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 sang) or (hieu van)) - canh manh cua ((hang cong) or (dang cong)) san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu van)) - canh manh cua ((hang cong) OR (dang cong)) san toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (hieu van)) - canh manh cua ((hang cong) or (dang cong)) san toan ban*.