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