Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hieu manh, nghiep nganh
hiem ngan » kim ngan, viem gan
tranh xay » trinh xay, trong xay, nganh xay
trong san » trong cac, cong san, dong san
manh xay » nganh xay, van xay, dang xay
san phan » san pham, van phan, sat phan
phan cau » phan dau, phan cac, phan tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu nganh) OR (hiem ngan)) - canh ((tranh xay) or (manh xay)) dung trong san phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu nganh) OR (hiem ngan)) - canh ((tranh xay) OR (manh xay)) dung trong san phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu nganh) OR (hiem ngan)) - canh ((tranh xay) or (manh xay)) dung trong san phan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu nganh) OR (hiem ngan)) - canh ((tranh xay) or (manh xay)) dung trong san phan cau*.