Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
trinh vi » trinh va, trinh ve, trinh viet
kho tang » cao tang
su sach » vu sach
van bao » van ban, van dao
so sach » so sanh, bo sach, co sach
tang xa » trang xa, tang ma, lang xa
cua tre » cua te, cuu tre, cua triet
loc va » hoc va
luc va » duc va, tuc va
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) kho tang xa hoi. hieu van bao ((loc va) OR (luc va)) trinh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) kho tang xa hoi. hieu van bao ((loc va) or (luc va)) trinh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) kho tang xa hoi. hieu van bao ((loc va) or (luc va)) trinh vi cua tre*.