Perhaps you should try some spelling variations:
hanh than » hanh han, hanh nhan, hanh phan
cua viet » ca viet, hoa viet, cua vat
nam thuc » nam thuoc, am thuc, nam thu
than cua » nhan cua, thai cua, ban cua
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
ky tang » ky nang, ky dang, kho tang
hoa hoi » khoa hoi, hoa hoc, hoc hoi
hoa doi » hoa dai, hoc doi, xoa doi
hieu ve » hieu van
hieu va » lieu va, hieu qua
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky tang ((hoa hoi) or (hoa doi)). ((hieu ve) or (hieu va)) nam thuc van hanh than cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky tang ((hoa hoi) OR (hoa doi)). ((hieu ve) OR (hieu va)) nam thuc van hanh than cua viet.
• Adding a wildcard symbol may retrieve word variants: te sac ky tang ((hoa hoi) or (hoa doi)). ((hieu ve) or (hieu va)) nam thuc van hanh than cua viet*.