Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cau thuc » cuu thuc, can thuc, cau phuc
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu van
sach v » sach va, sach y, sach 2
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van 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 v nang ma hoi. ((hieu ve) OR (hieu va)) ((cau thuc) OR (cau truc)) va hanh vi va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang ma hoi. ((hieu ve) or (hieu va)) ((cau thuc) OR (cau truc)) va hanh vi va triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach v nang ma hoi. ((hieu ve) or (hieu va)) ((cau thuc) OR (cau truc)) va hanh vi va triet*.