Perhaps you should try some spelling variations:
tinh bai » tinh bac, tinh hai, hinh bai
su sach » so sach, vu sach
bai cua » ban cua, dai cua, bai ca
va tinh » may tinh
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
ty hang » ly hang, ty xang, thi hang
ty tang » tay tang, ty xang, ky tang
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: su sach ((ty tang) or (ty hang)) xa hoi. ((hieu ve) or (hieu va)) coc luc va tinh bai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty tang) OR (ty hang)) xa hoi. ((hieu ve) OR (hieu va)) coc luc va tinh bai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ((ty tang) or (ty hang)) xa hoi. ((hieu ve) or (hieu va)) coc luc va tinh bai cua tre*.