Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
tu sach » thu sach, su sach, te sach
dua ban » dia ban, cua ban, mua ban
tai cua » thai cua, tai cuc, tri cua
qua ban » cua ban, qua quan
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
duc ban » duc tan, duc van, duc man
hieu va » lieu va, hieu qua
cao hoc » co hoc, cho hoc, chat hoc
va cam » va cham, va cac, va cao

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 ky nang cao hoc. hieu va cam ((duc ban) or (((dua ban) OR (qua ban)))) thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoc. hieu va cam ((duc ban) OR (((dua ban) OR (qua ban)))) thanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang cao hoc. hieu va cam ((duc ban) or (((dua ban) OR (qua ban)))) thanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hoc. hieu va cam ((duc ban) or (((dua ban) OR (qua ban)))) thanh tai cua tre*.