Perhaps you should try some spelling variations:
quang thanh » quan thanh, hoang thanh, muong thanh
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
cong quang » luong quang, thong quang, duong quang
thanh chau » thanh cha, thanh cham, thanh chu
trung cao » truong cao, trung cap, trung ca
tong cong » trong cong, cong cong, dung cong
trung co » trung bo, trong co, truong cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu sach - thanh ((trung cao) or (trung co)) tong cong quang thanh chau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - thanh ((trung cao) OR (trung co)) tong cong quang thanh chau.
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - thanh ((trung cao) or (trung co)) tong cong quang thanh chau*.