Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
qua ban » qua quan
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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) or (ma hoa)). hieu van nam ((qua ban) OR (cua ban)) thanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((xa hoi) OR (ma hoa)). hieu van nam ((qua ban) OR (cua ban)) thanh van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((xa hoi) or (ma hoa)). hieu van nam ((qua ban) OR (cua ban)) thanh van cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((xa hoi) or (ma hoa)). hieu van nam ((qua ban) OR (cua ban)) thanh van cua tre*.