Perhaps you should try some spelling variations:
nhung chong » nhung cong, nhung phong, nhung phuong
hieu nganh » vien nganh, hiem ngan, nghiep nganh
hieu manh » chieu xanh, dieu hanh, hien hanh
hanh sinh » hanh tinh, hanh dinh, hinh sinh
van toan » van tuan, van tan, van thanh
sinh va » sinh vat, tinh va, dinh van

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 sinh va nhung chong ((van toan) or (anh tuan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (hieu nganh)) - hanh sinh va nhung chong ((van toan) OR (anh tuan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) OR (hieu nganh)) - hanh sinh va nhung chong ((van toan) or (anh tuan)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) OR (hieu nganh)) - hanh sinh va nhung chong ((van toan) or (anh tuan)) cau*.