Perhaps you should try some spelling variations:
sach ky » sach y, sach ty, sach kem
qua cac » cua cac
dao cua » dai cua, day cua, dan cua
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) OR (sac ky)) nang x hoi. hieu qua cac ((xuc va) or (luc va)) lanh dao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) nang x hoi. hieu qua cac ((xuc va) OR (luc va)) lanh dao cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sac ky)) nang x hoi. hieu qua cac ((xuc va) or (luc va)) lanh dao cua tre*".