Perhaps you should try some spelling variations:
qua thanh » quan thanh, cua thanh, qua than
thanh duc » thach duc, 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
sac 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) OR (cac ky)) nang cao hoi. hieu qua thanh 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) OR (cac ky)) nang cao hoi. hieu qua thanh duc va ((hanh lai) OR (thanh lap)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sac ky) OR (cac ky)) nang cao hoi. hieu qua thanh duc va ((hanh lai) or (thanh lap)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sac ky) OR (cac ky)) nang cao hoi. hieu qua thanh duc va ((hanh lai) or (thanh lap)) cua tre*.