Perhaps you should try some spelling variations:
thanh lap » thanh san, phan lap, thanh hai
hanh lai » hanh lam, hanh tai, thanh loi
su sach » so sach, vu sach
cac luc » cau luc, coc luc, cac nuoc
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cai hoi » dai hoi, cai hoa, lai hoi
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
ve cac » va cac, vien cac

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

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