Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
hieu van » hieu va, thien van, lieu va
nang xa » lang xa, nang ma, mang xa
van cac » van hac, van cau, van bac
cac toi » cac thoi
toi gia » toi gian, tri gia, toc gia
cua tre » cua te, cuu tre, cua triet
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky ((nang xa) or (nang x)) hoi. hieu van cac toi gia thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((nang xa) OR (nang x)) hoi. hieu van cac toi gia thanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu can ky ((nang xa) or (nang x)) hoi. hieu van cac toi gia thanh dai cua tre*.