Perhaps you should try some spelling variations:
hanh truong » hanh trong, anh truong, manh truong
truong cao » truong dai
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
cao nhung » cho nhung, cam nhung, cao chung
doc hieu » toc thieu, hoc thieu, hoc hien
tan toan » tap toan, van toan, dan toan

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 - hanh truong cao nhung cong ((tan toan) or (tan tran)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu lang - hanh truong cao nhung cong ((tan toan) OR (tan tran)) cao.
• Adding a wildcard symbol may retrieve word variants: doc hieu lang - hanh truong cao nhung cong ((tan toan) or (tan tran)) cao*.