Perhaps you should try some spelling variations:
hien nhanh » hien hanh, thien thanh, tien thanh
canh trinh » canh tranh, hanh trinh, canh tinh
thang nong » thang long, hang nong, tang nong
thanh cac » hanh cac, thanh bac, thanh ca
trinh va » trinh van, trinh vat, trinh ve
va thang » van thang, va thanh, va thong
nong dan » cong dan, nong san, nguong dan
khan cap » khan ap, than cap, khoan cam

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 nhanh - canh trinh va thang nong dan ((khan cap) or (thanh cac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien nhanh - canh trinh va thang nong dan ((khan cap) OR (thanh cac)).
• Adding a wildcard symbol may retrieve word variants: hoc hien nhanh - canh trinh va thang nong dan ((khan cap) or (thanh cac))*.