Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
vat hanh » vat thanh, van hanh, va hanh
va triet » va thiet, va trien, ve triet
so sach » so sanh, bo sach, co sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
va cham » va chat, va tham
y nang » ly nang, v nang, may nang
vi va » vi van, vai va, vu 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: so sach ((y nang) OR (ky nang)) ((mai hoi) OR (ma hoa)). hieu va cham thuc vat hanh vi va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((y nang) OR (ky nang)) ((mai hoi) or (ma hoa)). hieu va cham thuc vat hanh vi va triet~".
• Adding a wildcard symbol may retrieve word variants: so sach ((y nang) OR (ky nang)) ((mai hoi) or (ma hoa)). hieu va cham thuc vat hanh vi va triet*.