Perhaps you should try some spelling variations:
thanh lai » thanh hai, thanh lap, thanh loi
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
dua ban » dia ban, qua ban, mua ban
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, me hoi

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

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