Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van lam » van nam
su sach » so sach, vu sach
xay hoi » xa hoi, tay hoi, cay phoi
ty hang » ly hang, ty xang, thi hang
ty dang » ty xang, ky dang, ty dong
cua tre » cua te, cuu tre, cua triet
loc 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: su sach ((ty dang) OR (ty hang)) xay hoi. hieu van lam ((loc va) or (hoc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty dang) OR (ty hang)) xay hoi. hieu van lam ((loc va) OR (hoc va)) hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty dang) OR (ty hang)) xay hoi. hieu van lam ((loc va) or (hoc va)) hanh vi cua tre*".