Perhaps you should try some spelling variations:
vien nganh » vien thanh
nhung cong » dung cong, thong cong, hang cong
hiem ngan » kim ngan, viem gan
trang va » tran van
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, 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) or (vien nganh)) - hanh ((trang va) OR (hang va)) nhung cong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hiem ngan) OR (vien nganh)) - hanh ((trang va) OR (hang va)) nhung cong dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hiem ngan) or (vien nganh)) - hanh ((trang va) OR (hang va)) nhung cong dan toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((hiem ngan) or (vien nganh)) - hanh ((trang va) OR (hang va)) nhung cong dan toan cao*.