Perhaps you should try some spelling variations:
hiem ngan » kim ngan, viem gan
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
nhung don » nhung van, nhung bo
hang cong » dang cong, hang nong, bang cong
hoc hiem » hoc hien, hoc thieu, hoc thiet
tinh cua » trinh cua, sinh cua, tinh chat
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 hiem ngan - hanh tinh cua ((nhung don) or (hang cong)) ((san toan) or (dan toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hiem ngan - hanh tinh cua ((nhung don) OR (hang cong)) ((san toan) OR (dan toan)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc hiem ngan - hanh tinh cua ((nhung don) or (hang cong)) ((san toan) or (dan toan)) cao*.