Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sang » thieu khang, thieu quang, hieu lang
chieu sang » chieu sach, chieu xanh, hieu lang
dung duong » dong duong, dung dung, dung luong
trung qua » trung quan, trong qua, trung cua
dung dong » dung cong, vung dong, dung trong
manh toan » thanh toan, anh tuan, tinh 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 ((thieu sang) or (chieu sang)) - thanh trung qua ((dung duong) OR (dung dong)) manh toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (chieu sang)) - thanh trung qua ((dung duong) OR (dung dong)) manh toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (chieu sang)) - thanh trung qua ((dung duong) OR (dung dong)) manh toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (chieu sang)) - thanh trung qua ((dung duong) OR (dung dong)) manh toan ban*.