Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
hien hanh » dieu hanh
hanh tran » hanh trang, thanh tran, hanh tram
tran canh » tran manh, tran anh, tran danh
canh dung » canh duong, anh dung, manh dung
dung cong » dung trong
san toan » van toan, manh toan, xuan toan
dan toan » van toan, dan than, manh toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien hanh) or (hieu nganh)) - hanh tran canh dung cong ((san toan) or (dan toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien hanh) OR (hieu nganh)) - hanh tran canh dung cong ((san toan) OR (dan toan)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((hien hanh) or (hieu nganh)) - hanh tran canh dung cong ((san toan) or (dan toan)) cao*.