Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
luc va » duc va, tuc va, loc va

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

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