Perhaps you should try some spelling variations:
chieu quang » hieu quang, thieu quang, chu quang
trung tuan » trung thanh, trung tam, tran tuan
trung cua » truong cua, trung cap, dung cua
ho chieu » theo chieu, hoc thieu, doi chieu
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu quang - thanh ((trung cua) OR (trung tuan)) trong cong ((dan toan) OR (dan than)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu quang - thanh ((trung cua) or (trung tuan)) trong cong ((dan toan) OR (dan than)) cau~".
• Adding a wildcard symbol may retrieve word variants: ho chieu quang - thanh ((trung cua) or (trung tuan)) trong cong ((dan toan) OR (dan than)) cau*.