Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh tai » thanh hai, thanh toan, doanh tai
cua tre » cuu tre, cua triet, dua tren
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
sach ky » sach y, sach ty, sach kem
cac cuu » cap cuu, cac cau, cac chu
cuu ban » cuu van, cua ban, cuu san
ve cac » va cac, vien cac
sac ky » cac ky, sai ky
cua te » cua tu

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