Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh dai » hanh tai, hanh dao, vanh dai
tu bach » vu bach, tu cach, tu bac
nang xa » nang x, lang xa, nang ma
lang ha » long ha
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu bach mai ((nang xa) or (lang ha)) hoi. hieu va cam duc van hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu bach mai ((nang xa) OR (lang ha)) hoi. hieu va cam duc van hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu bach mai ((nang xa) or (lang ha)) hoi. hieu va cam duc van hanh dai cua tre*.