Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, hieu lang
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, thong cong, hang cong
trung va » truong va, trang va, trung ha
cong tac » cong ty
tac toan » tap toan, tam toan, hach 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: ho ((chieu sang) or (hieu quang)) - thanh trung va nhung cong tac toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu quang)) - thanh trung va nhung cong tac toan ban.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu quang)) - thanh trung va nhung cong tac toan ban*.