Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh tai » thanh hai, thanh toan, doanh tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoc » co hoc, cho hoc, chat hoc
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, pham duc
duc ban » duc tan, duc van, dua ban
cuc tre » duc tre, cuu tre, cuoc tro
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam

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 ve cam duc ban thanh tai ((((cuc tre) or (cuc thue))) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoc. hieu ve cam duc ban thanh tai ((((cuc tre) OR (cuc thue))) OR (cua tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hoc. hieu ve cam duc ban thanh tai ((((cuc tre) or (cuc thue))) or (cua tre))*.