Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, nghiep nganh
hieu manh » chieu xanh, dieu hanh, hien hanh
trong san » trong cac, cong san, dong san
than cua » nhan cua, thai cua, ban cua
tang cua » mang cua, hang cua, tang luan
san toan » van toan, dan toan, manh toan
toan ban » van ban

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 manh) OR (hieu nganh)) - hanh ((than cua) or (tang cua)) dung trong san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (hieu nganh)) - hanh ((than cua) OR (tang cua)) dung trong san toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) OR (hieu nganh)) - hanh ((than cua) or (tang cua)) dung trong san toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) OR (hieu nganh)) - hanh ((than cua) or (tang cua)) dung trong san toan ban*.