Perhaps you should try some spelling variations:
hanh truong » hanh trong, anh truong, manh truong
chieu sang » chieu sach, chieu xanh, nhieu tang
truong cua » truong ca, truong quan, truong cao
nhung cong » dung cong, thong cong, hang cong
hieu lang » hieu quang, 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: hoc ((chieu sang) or (hieu lang)) - hanh truong cua nhung cong ((dan toan) OR (dan than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - hanh truong cua nhung cong ((dan toan) OR (dan than)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) or (hieu lang)) - hanh truong cua nhung cong ((dan toan) OR (dan than)) cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (hieu lang)) - hanh truong cua nhung cong ((dan toan) OR (dan than)) cao*.