Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
y nang » ky nang, ly nang, v nang
va lam » van lam, va lap
lam tu » nam tu, cam tu, dam tu
va dan » ca dan, va dao, va dau
ki su » ky su

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 y nang x ho. hieu va lam tu ((ban thanh) or (va dan)) ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x ho. hieu va lam tu ((ban thanh) OR (va dan)) ki su triet.
• Adding a wildcard symbol may retrieve word variants: su sach y nang x ho. hieu va lam tu ((ban thanh) or (va dan)) ki su triet*.