Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
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
tuc va » thuc va, truc va, tuc xa
loc va » hoc va, luc va
vi cua » vai cua, di 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) or (lieu va)) cam ((tuc va) or (loc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. ((hieu van) OR (lieu va)) cam ((tuc va) OR (loc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. ((hieu van) or (lieu va)) cam ((tuc va) or (loc va)) hanh vi cua tre*.