Perhaps you should try some spelling variations:
hieu va » lieu va, hieu qua
cac duc » cac du, cac dac, cac nuoc
cao duc » dao duc, cao suc, giao duc
va danh » va dinh, va dan, va hanh
danh di » danh du, xanh di, danh dien
cua tre » cua te, cuu tre, cua triet
te cac » tu cac, ve cac, de cac
te cao » te bao
di cua » dai cua, doi cua, de cua

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: ((te cac) OR (te cao)) ky nang x ho. hieu va ((cac duc) OR (cao duc)) va danh di cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te cac) OR (te cao)) ky nang x ho. hieu va ((cac duc) or (cao duc)) va danh di cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te cac) OR (te cao)) ky nang x ho. hieu va ((cac duc) or (cao duc)) va danh di cua tre*.