Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hieu manh, nghiep nganh
hiem ngan » kim ngan, viem gan
canh manh » lanh manh, canh tranh, cach mang
cua dung » cua dang, cua dong, cua rung
qua dung » quang dung, su dung, qua song
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai 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: toc ((hieu nganh) OR (hiem ngan)) - canh manh ((cua dung) OR (qua dung)) cong tap toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((hieu nganh) OR (hiem ngan)) - canh manh ((cua dung) OR (qua dung)) cong tap toan cao".
• Adding a wildcard symbol may retrieve word variants: toc ((hieu nganh) OR (hiem ngan)) - canh manh ((cua dung) OR (qua dung)) cong tap toan cao*.