Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
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 nham » va cham, va tham, va nha
y nang » ky nang, ly nang, v 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 ((mai hoi) OR (ma hoa)). hieu va nham thuc vat hanh vi va triet~.
• Adding a wildcard symbol may retrieve word variants: so sach y nang ((mai hoi) or (ma hoa)). hieu va nham thuc vat hanh vi va triet*.