Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ban thanh » ban hanh, ban hang
sach ky » sac ky, sach y, sach ty
tai cua » thai cua, tai cuc, tri cua
cuu ban » cuu van, cua ban, cuu san
cac cuu » cap cuu, cac cau, cac chu
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac

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