Perhaps you should try some spelling variations:
qua thach » qua thanh, quan thanh, cua thanh
thach duc » thach thuc, than duc, thinh duc
thanh lap » thanh san, phan lap, thanh hai
hanh lai » hanh lam, hanh tai, thanh loi
cao hoi » cau hoi, co hoi, cao hoc
cua tre » cua te, cuu tre, cua triet
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky nang cao hoi. hieu qua thach duc va ((hanh lai) or (thanh lap)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang cao hoi. hieu qua thach duc va ((hanh lai) OR (thanh lap)) cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky nang cao hoi. hieu qua thach duc va ((hanh lai) or (thanh lap)) cua tre*.