Perhaps you should try some spelling variations:
cua truong » cua trung, xuan truong, cac truong
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
lanh ban » lanh bang, lang ban, doanh ban
dong dan » dong danh, duong dan, cong dan
dong san » cong san, dong bang, dong von
ban cua » ban quan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sang) OR (hieu lang)) - lanh ban cua truong ((dong dan) or (dong san)) phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - lanh ban cua truong ((dong dan) OR (dong san)) phan tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) OR (hieu lang)) - lanh ban cua truong ((dong dan) or (dong san)) phan tu".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) OR (hieu lang)) - lanh ban cua truong ((dong dan) or (dong san)) phan tu*.