Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, nhung don
hiem ngan » kim ngan, viem gan
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
hoc hiem » hoc hien, hoc thieu, hoc thiet
tinh cua » trinh cua, sinh cua, tinh chat
san toan » van toan, dan toan, manh toan
toan cao » toan ban, toan tap

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 cong) or (((hang cong) OR (dang cong)))) san toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hiem ngan - hanh tinh cua ((nhung cong) OR (((hang cong) OR (dang cong)))) san toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hiem ngan - hanh tinh cua ((nhung cong) or (((hang cong) OR (dang cong)))) san toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc hiem ngan - hanh tinh cua ((nhung cong) or (((hang cong) OR (dang cong)))) san toan cao*.