Perhaps you should try some spelling variations:
thanh tinh » thanh binh, nhanh tinh, than kinh
hieu nganh » vien nganh, hieu manh, nghiep nganh
thong cong » trong cong, tong cong, thong thong
hiem ngan » kim ngan, viem gan
hanh tinh » hanh trinh, nhanh tinh, canh tinh
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan tap » toan ban

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 nganh) OR (hiem ngan)) - ((hanh tinh) or (thanh tinh)) he thong cong dan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu nganh) OR (hiem ngan)) - ((hanh tinh) OR (thanh tinh)) he thong cong dan toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu nganh) OR (hiem ngan)) - ((hanh tinh) or (thanh tinh)) he thong cong dan toan tap".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu nganh) OR (hiem ngan)) - ((hanh tinh) or (thanh tinh)) he thong cong dan toan tap*.