Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
cau thuc » cau truc, cuu thuc, can thuc
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu van
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
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: tu sach y nang mai hoi. ((hieu ve) OR (hieu va)) cau thuc va hanh vi va triet~.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang mai hoi. ((hieu ve) or (hieu va)) cau thuc va hanh vi va triet*.