Perhaps you should try some spelling variations:
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
duc ban » duc tan, duc van, dua ban
cac ban » cac dan, cac van, can ban
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
hieu v » hieu va, hieu ve, hieu 2
v pham » vi pham, d pham

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ma hoa. hieu v pham ((duc ban) or (cac ban)) doanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoa. hieu v pham ((duc ban) OR (cac ban)) doanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoa. hieu v pham ((duc ban) or (cac ban)) doanh tai cua tre*.