Perhaps you should try some spelling variations:
thanh lap » thanh san, phan lap, thanh hai
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
hanh lai » hanh lam, hanh tai, thanh loi
tham du » thap du, tham do, pham duc
sach ky » sac ky, sach y, sach ty
cao hoi » co hoi, cao hoc, tao hoi
cua tre » cua te, cuu tre, cua triet
du va » dau va, tu va, su va

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

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