Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
nang xa » nang x, lang xa, mang xa
truc va » thuc va, thuc vat, trung va
van cau » van dau, van hau, van chat
nang ma » tang ma, sang ma, nang cao
sac ky » cac 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 ((sac ky) or (sai ky)) ((nang xa) OR (nang ma)) hoi. hieu van cau truc va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sai ky)) ((nang xa) OR (nang ma)) hoi. hieu van cau truc va hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sac ky) or (sai ky)) ((nang xa) OR (nang ma)) hoi. hieu van cau truc va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sai ky)) ((nang xa) OR (nang ma)) hoi. hieu van cau truc va hanh vai cua tre*.