Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
cham duc » pham duc, cham soc, pham duy
dinh chi » dinh thi, dinh tri, dinh moi
nang doc » nang luc
banh di » danh di, xanh di, banh chi
duc ban » duc tan, duc van, dua ban
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((nang o) or (nang doc)) hai. hieu qua cham duc ban ((banh di) or (dinh chi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang o) OR (nang doc)) hai. hieu qua cham duc ban ((banh di) OR (dinh chi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang o) or (nang doc)) hai. hieu qua cham duc ban ((banh di) or (dinh chi)) cua tre*.