Perhaps you should try some spelling variations:
thanh trung » thanh tung
trung cong » truong cong, trong cong, trung uong
hieu lang » chieu sang, hieu quang, nhieu tang
trung cua » truong cua, trung tuan, trung cap
cua trung » cua truong, xuan trung, cua nhung
hoc hieu » hoc thieu, hoc hien, doc hieu
van tuan » van quan, anh tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - thanh trung cua trung cong ((van tuan) or (van ban)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - thanh trung cua trung cong ((van tuan) OR (van ban)) cau.
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - thanh trung cua trung cong ((van tuan) or (van ban)) cau*.