Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van chat » cao chat
thanh va » thanh van, hanh va, thanh ha
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
goc va » hoc va, doc va, uoc va
loc va » hoc va, luc va
va cua » va chua, via cua, ca cua

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 chat ((goc va) or (loc va)) thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. hieu van chat ((goc va) OR (loc va)) thanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. hieu van chat ((goc va) or (loc va)) thanh va cua tre*.