Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
cham cuc » cham cuu, pham cuc, pham chuc
hanh va » hang va, hanh vi
cuc ban » cua ban, cac ban, cuu ban
sach ky » sac ky, sach y, sach ty
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet

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 ((lang xa) or (nang ma)) hoi. hieu qua cham cuc ban ((anh va) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((lang xa) OR (nang ma)) hoi. hieu qua cham cuc ban ((anh va) OR (hanh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ky ((lang xa) or (nang ma)) hoi. hieu qua cham cuc ban ((anh va) or (hanh va)) cua tre*.