Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
mang xa » lang xa, mang may, dang xay
sang ma » tang ma, nang ma, sang tao
hieu va » lieu va, hieu qua
cac duc » cac du, cac dac, cac nuoc
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky ((mang xa) or (sang ma)) hoi. hieu va ((cac duc) or (cao duc)) va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky ((mang xa) OR (sang ma)) hoi. hieu va ((cac duc) OR (cao duc)) va hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu cac ky ((mang xa) or (sang ma)) hoi. hieu va ((cac duc) or (cao duc)) va hanh dai cua tre*.