Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
nhung hong » nhung chong, nhung huong, nhung phong
hien hanh » dieu hanh
hanh sinh » hanh tinh, hanh dinh, hinh sinh
van tuan » van ban, anh tuan
van quan » van ban
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 ((hien hanh) or (hieu nganh)) - hanh sinh va nhung hong ((van tuan) OR (van quan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien hanh) OR (hieu nganh)) - hanh sinh va nhung hong ((van tuan) OR (van quan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien hanh) or (hieu nganh)) - hanh sinh va nhung hong ((van tuan) OR (van quan)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien hanh) or (hieu nganh)) - hanh sinh va nhung hong ((van tuan) OR (van quan)) cau*.