Perhaps you should try some spelling variations:
thuc van » thuc vat, thuc dan, thuc va
cua viet » hoa viet, cua vat, cua dieu
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
ca viet » va viet, co viet, hoa viet
hoc hoi » hoc khoi, hoc hoa, hoc noi
hieu ve » hieu va, hieu van
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ho hoi » hoa hoi, hoi hoi, co hoi
ve nam » he nam, va nam, le nam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang ((ho hoi) OR (hoc hoi)). hieu ve nam thuc van hanh vi ((cua viet) OR (ca viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang ((ho hoi) or (hoc hoi)). hieu ve nam thuc van hanh vi ((cua viet) OR (ca viet))~".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ((ho hoi) or (hoc hoi)). hieu ve nam thuc van hanh vi ((cua viet) OR (ca viet))*.