Perhaps you should try some spelling variations:
hanh truong » hanh trong, anh truong, manh truong
hieu quang » thieu quang, hieu quan, hieu qua
truong cua » truong ca, truong quan, truong cao
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, nhieu tang, hieu van
cua nhung » va nhung
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.

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((hieu lang) OR (hieu quang)) - hanh truong cua nhung cong ((dan toan) or (dan than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu lang) OR (hieu quang)) - hanh truong cua nhung cong ((dan toan) OR (dan than)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu lang) OR (hieu quang)) - hanh truong cua nhung cong ((dan toan) or (dan than)) cau".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu lang) OR (hieu quang)) - hanh truong cua nhung cong ((dan toan) or (dan than)) cau*.