Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ban thanh » ban hanh, ban hang
chat duc » chat xuc, chat doc, chet duoc
tai cua » thai cua, tai cuc, tri cua
duc ban » duc tan, duc van, dua ban
va chat » van chat, va phat, cao chat
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach thu, xach tay
nang xa » lang xa, nang ma, mang xa
sach tu » sach thu, cach tu, sach uu

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