Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, te sach, tu cach
vai cua » dai cua, hai cua, lai cua
chuc va » thuc va, thuc vat
phuc va » phuc vu, thuc va, thuc vat
van cau » van dau, van hau, van chat
vang xa » lang xa, mang xa, ang xa
ly vang » ly hang, ly van, ly quang
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet

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: ((tu sach) OR (su sach)) ly vang xa hoi. hieu van cau ((phuc va) OR (chuc va)) hanh vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ly vang xa hoi. hieu van cau ((phuc va) or (chuc va)) hanh vai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ly vang xa hoi. hieu van cau ((phuc va) or (chuc va)) hanh vai cua tre*.