Perhaps you should try some spelling variations:
thanh tung » thanh cong
hanh trinh » canh tranh, hanh chinh
nhung cong » thong cong, hang cong, nhung don
thanh phan » thanh pho, thanh san, thanh toan
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
phan cau » phan dau, phan cac, phan tu

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 lang - ((thanh tung) or (hanh trinh)) cua ((nhung cong) OR (dung cong)) thanh phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu lang - ((thanh tung) OR (hanh trinh)) cua ((nhung cong) OR (dung cong)) thanh phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu lang - ((thanh tung) or (hanh trinh)) cua ((nhung cong) OR (dung cong)) thanh phan cau".
• Adding a wildcard symbol may retrieve word variants: doc hieu lang - ((thanh tung) or (hanh trinh)) cua ((nhung cong) OR (dung cong)) thanh phan cau*.