Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
va triet » va thiet, va trien, ve triet
su triet » su viet, su tien, ve triet
thanh vi » hanh vi, thanh va, thanh ve
vu sach » vu bach, su sach, vu khach
hieu va » lieu va
nang ma » tang ma, sang ma, nang cao
chat tu » nhat tu, chai tu, chay tu
y nang » ky nang, ly nang, v nang
tu ban » thu ban, te ban
ma hoi » mai hoi, xa hoi, ma hoa

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