Perhaps you should try some spelling variations:
ban hang » ngan hang
va triet » va thiet, va trien, ve triet
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
su viet » so viet
va dan » ca dan, va dao, va dau

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: su sach ty nang x ho. hieu va cac tuc ((ban hang) OR (va dan)) vi ((su viet) OR (va triet))~.
• Adding a wildcard symbol may retrieve word variants: su sach ty nang x ho. hieu va cac tuc ((ban hang) or (va dan)) vi ((su viet) or (va triet))*.