Perhaps you should try some spelling variations:
ban hang » ngan hang
su triet » su viet, su tien, ve triet
va triet » va thiet, va trien, ve triet
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
chat te » chat deo, chat tai, chat beo
hang vi » hang va, hanh vi, hang di
y nang » ly nang, v nang, may nang
te ban » te bao

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ((y nang) OR (ky nang)) xa hoi. hieu va chat te ban hang vi ((su triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((y nang) OR (ky nang)) xa hoi. hieu va chat te ban hang vi ((su triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((y nang) OR (ky nang)) xa hoi. hieu va chat te ban hang vi ((su triet) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: vu sach ((y nang) OR (ky nang)) xa hoi. hieu va chat te ban hang vi ((su triet) or (va triet))*.