Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh hai » thanh hai, nhanh hai, hang hai
thuc dan » thuc hanh, hoc dan
hai cua » thai cua, dai cua, hoi cua
hieu ve » hieu va, hieu van
hoa doi » hoa dai, hoc doi, xoa doi
hoa hoi » khoa hoi, hoa hoc, hoc hoi
ky lang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
ve nam » he nam, va nam, le nam
te sac » te sach, te cac, te san

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 lang ((hoa hoi) or (hoa doi)). hieu ve nam ((thuc vat) or (thuc dan)) hanh hai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky lang ((hoa hoi) OR (hoa doi)). hieu ve nam ((thuc vat) OR (thuc dan)) hanh hai cua viet.
• Adding a wildcard symbol may retrieve word variants: te sac ky lang ((hoa hoi) or (hoa doi)). hieu ve nam ((thuc vat) or (thuc dan)) hanh hai cua viet*.