Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vai » thanh hai, thanh van, thanh tai
va trien » va truyen, va thiet, va tuyen
sach ky » sac ky, sach y, sach ty
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cuu ban » cuu van, cua ban, cuu san
va cap » va cac, va dap, va cao
vai va » mai va, dai va, hai va

You may be able to get more results by adjusting your search query.

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